21073236488640 has 560 divisors, whose sum is σ = 85687891819200. Its totient is φ = 4815731294208.

The previous prime is 21073236488639. The next prime is 21073236488641. The reversal of 21073236488640 is 4688463237012.

21073236488640 is a `hidden beast` number, since 2 + 1 + 0 + 73 + 2 + 36 + 488 + 64 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21073236488639) and next prime (21073236488641).

It is a tau number, because it is divible by the number of its divisors (560).

It is a super-3 number, since 3×21073236488640³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21073236488641) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1184612866 + ... + 1184630654.

Almost surely, 2^{21073236488640} is an apocalyptic number.

21073236488640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21073236488640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42843945909600).

21073236488640 is an abundant number, since it is smaller than the sum of its proper divisors (64614655330560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21073236488640 is a wasteful number, since it uses less digits than its factorization.

21073236488640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24354 (or 24335 counting only the distinct ones).

The product of its (nonzero) digits is 9289728, while the sum is 54.

The spelling of 21073236488640 in words is "twenty-one trillion, seventy-three billion, two hundred thirty-six million, four hundred eighty-eight thousand, six hundred forty".