21437360640 has 320 divisors, whose sum is σ = 76458856320. Its totient is φ = 5693276160.

The previous prime is 21437360639. The next prime is 21437360663. The reversal of 21437360640 is 4606373412.

It is a happy number.

21437360640 is a `hidden beast` number, since 2 + 1 + 4 + 3 + 7 + 3 + 6 + 0 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (320).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21437360595 and 21437360604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22878252 + ... + 22879188.

It is an arithmetic number, because the mean of its divisors is an integer number (238933926).

Almost surely, 2^21437360640 is an apocalyptic number.

21437360640 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 21437360640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38229428160).

21437360640 is an abundant number, since it is smaller than the sum of its proper divisors (55021495680).

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

21437360640 is an equidigital number, since it uses as much as digits as its factorization.

21437360640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1300 (or 1278 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 36.

The spelling of 21437360640 in words is "twenty-one billion, four hundred thirty-seven million, three hundred sixty thousand, six hundred forty".