20663213643 has 12 divisors (see below), whose sum is σ = 30952303928. Its totient is φ = 13775475600.

The previous prime is 20663213629. The next prime is 20663213647. The reversal of 20663213643 is 34631236602.

20663213643 is a `hidden beast` number, since 2 + 0 + 6 + 6 + 3 + 2 + 1 + 3 + 643 = 666.

It is not a de Polignac number, because 20663213643 - 2³³ = 12073279051 is a prime.

It is a super-2 number, since 2×20663213643² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20663213598 and 20663213607.

It is not an unprimeable number, because it can be changed into a prime (20663213647) 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, 42516658 + ... + 42517143.

Almost surely, 2^20663213643 is an apocalyptic number.

20663213643 is a deficient number, since it is larger than the sum of its proper divisors (10289090285).

20663213643 is an frugal number, since it uses more digits than its factorization.

20663213643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85033816 (or 85033804 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 36.

The spelling of 20663213643 in words is "twenty billion, six hundred sixty-three million, two hundred thirteen thousand, six hundred forty-three".