21920085513 has 8 divisors (see below), whose sum is σ = 32474200800. Its totient is φ = 14613390324.

The previous prime is 21920085419. The next prime is 21920085541. The reversal of 21920085513 is 31558002912.

It is a de Polignac number, because none of the positive numbers 2^k-21920085513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21920085563) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 405927483 + ... + 405927536.

It is an arithmetic number, because the mean of its divisors is an integer number (4059275100).

Almost surely, 2^21920085513 is an apocalyptic number.

It is an amenable number.

21920085513 is a deficient number, since it is larger than the sum of its proper divisors (10554115287).

21920085513 is an equidigital number, since it uses as much as digits as its factorization.

21920085513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 811855028 (or 811855022 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The spelling of 21920085513 in words is "twenty-one billion, nine hundred twenty million, eighty-five thousand, five hundred thirteen".