21368096640 has 1152 divisors, whose sum is σ = 89392343040. Its totient is φ = 4683571200.

The previous prime is 21368096639. The next prime is 21368096657. The reversal of 21368096640 is 4669086312.

It is a tau number, because it is divible by the number of its divisors (1152).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 496932459 + ... + 496932501.

It is an arithmetic number, because the mean of its divisors is an integer number (77597520).

Almost surely, 2^21368096640 is an apocalyptic number.

21368096640 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 21368096640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44696171520).

21368096640 is an abundant number, since it is smaller than the sum of its proper divisors (68024246400).

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

21368096640 is a wasteful number, since it uses less digits than its factorization.

21368096640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The spelling of 21368096640 in words is "twenty-one billion, three hundred sixty-eight million, ninety-six thousand, six hundred forty".