20643501042 has 24 divisors (see below), whose sum is σ = 44745768444. Its totient is φ = 6878369664.

The previous prime is 20643501041. The next prime is 20643501049. The reversal of 20643501042 is 24010534602.

20643501042 is a `hidden beast` number, since 2 + 0 + 643 + 5 + 0 + 10 + 4 + 2 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 20591963001 + 51538041 = 143499^2 + 7179^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20643500997 and 20643501015.

It is not an unprimeable number, because it can be changed into a prime (20643501041) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 187363 + ... + 276390.

Almost surely, 2^20643501042 is an apocalyptic number.

20643501042 is an abundant number, since it is smaller than the sum of its proper divisors (24102267402).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20643501042 is a wasteful number, since it uses less digits than its factorization.

20643501042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 466234 (or 466231 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The spelling of 20643501042 in words is "twenty billion, six hundred forty-three million, five hundred one thousand, forty-two".