21531111304513 has 16 divisors (see below), whose sum is σ = 23810643999360. Its totient is φ = 19382699609856.

The previous prime is 21531111304511. The next prime is 21531111304517. The reversal of 21531111304513 is 31540311113512.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21531111304513 - 2¹ = 21531111304511 is a prime.

It is a super-2 number, since 2×21531111304513² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21531111304511) 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, 290053581 + ... + 290127802.

It is an arithmetic number, because the mean of its divisors is an integer number (1488165249960).

Almost surely, 2^{21531111304513} is an apocalyptic number.

It is an amenable number.

21531111304513 is a deficient number, since it is larger than the sum of its proper divisors (2279532694847).

21531111304513 is a wasteful number, since it uses less digits than its factorization.

21531111304513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 580181496.

The product of its (nonzero) digits is 5400, while the sum is 31.

The spelling of 21531111304513 in words is "twenty-one trillion, five hundred thirty-one billion, one hundred eleven million, three hundred four thousand, five hundred thirteen".