21507532647345 has 64 divisors (see below), whose sum is σ = 39569618880000. Its totient is φ = 11070793214208.

The previous prime is 21507532647319. The next prime is 21507532647361. The reversal of 21507532647345 is 54374623570512.

21507532647345 is a `hidden beast` number, since 2 + 1 + 5 + 0 + 7 + 532 + 64 + 7 + 3 + 45 = 666.

It is not a de Polignac number, because 21507532647345 - 2¹¹ = 21507532645297 is a prime.

It is a super-2 number, since 2×21507532647345² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21507532647291 and 21507532647300.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8901732 + ... + 11056938.

It is an arithmetic number, because the mean of its divisors is an integer number (618275295000).

Almost surely, 2^{21507532647345} is an apocalyptic number.

It is an amenable number.

21507532647345 is a deficient number, since it is larger than the sum of its proper divisors (18062086232655).

21507532647345 is a wasteful number, since it uses less digits than its factorization.

21507532647345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2157799 (or 2157793 counting only the distinct ones).

The product of its (nonzero) digits is 21168000, while the sum is 54.

The spelling of 21507532647345 in words is "twenty-one trillion, five hundred seven billion, five hundred thirty-two million, six hundred forty-seven thousand, three hundred forty-five".