20479561641 has 64 divisors (see below), whose sum is σ = 37856931840. Its totient is φ = 10630206720.

The previous prime is 20479561631. The next prime is 20479561699. The reversal of 20479561641 is 14616597402.

20479561641 is a `hidden beast` number, since 2 + 0 + 47 + 9 + 561 + 6 + 41 = 666.

It is not a de Polignac number, because 20479561641 - 2²⁵ = 20446007209 is a prime.

It is a super-2 number, since 2×20479561641² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20479561631) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3225516 + ... + 3231858.

It is an arithmetic number, because the mean of its divisors is an integer number (591514560).

Almost surely, 2^20479561641 is an apocalyptic number.

20479561641 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20479561641 is a deficient number, since it is larger than the sum of its proper divisors (17377370199).

20479561641 is a wasteful number, since it uses less digits than its factorization.

20479561641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7923 (or 7917 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The spelling of 20479561641 in words is "twenty billion, four hundred seventy-nine million, five hundred sixty-one thousand, six hundred forty-one".