21069925643640 has 128 divisors (see below), whose sum is σ = 63260219937600. Its totient is φ = 5614164541440.

The previous prime is 21069925643639. The next prime is 21069925643659. The reversal of 21069925643640 is 4634652996012.

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, 1353317776 + ... + 1353333344.

Almost surely, 2^{21069925643640} is an apocalyptic number.

21069925643640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21069925643640 is an abundant number, since it is smaller than the sum of its proper divisors (42190294293960).

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

21069925643640 is a wasteful number, since it uses less digits than its factorization.

21069925643640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23857 (or 23853 counting only the distinct ones).

The product of its (nonzero) digits is 16796160, while the sum is 57.

The spelling of 21069925643640 in words is "twenty-one trillion, sixty-nine billion, nine hundred twenty-five million, six hundred forty-three thousand, six hundred forty".