21507574243709 has 16 divisors (see below), whose sum is σ = 22214083445760. Its totient is φ = 20801862650880.

The previous prime is 21507574243699. The next prime is 21507574243733. The reversal of 21507574243709 is 90734247570512.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21507574243709 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21507574240709) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 583048064 + ... + 583084950.

It is an arithmetic number, because the mean of its divisors is an integer number (1388380215360).

Almost surely, 2^{21507574243709} is an apocalyptic number.

It is an amenable number.

21507574243709 is a deficient number, since it is larger than the sum of its proper divisors (706509202051).

21507574243709 is a wasteful number, since it uses less digits than its factorization.

21507574243709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47180.

The product of its (nonzero) digits is 14817600, while the sum is 56.

The spelling of 21507574243709 in words is "twenty-one trillion, five hundred seven billion, five hundred seventy-four million, two hundred forty-three thousand, seven hundred nine".