642739563 has 8 divisors (see below), whose sum is σ = 952206800. Its totient is φ = 428493024.

The previous prime is 642739561. The next prime is 642739583. The reversal of 642739563 is 365937246.

642739563 is a `hidden beast` number, since 64 + 27 + 3 + 9 + 563 = 666.

It is not a de Polignac number, because 642739563 - 2¹ = 642739561 is a prime.

It is a super-2 number, since 2×642739563² = 826228291690861938, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642739561) 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, 11902558 + ... + 11902611.

It is an arithmetic number, because the mean of its divisors is an integer number (119025850).

Almost surely, 2^642739563 is an apocalyptic number.

642739563 is a deficient number, since it is larger than the sum of its proper divisors (309467237).

642739563 is a wasteful number, since it uses less digits than its factorization.

642739563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23805178 (or 23805172 counting only the distinct ones).

The product of its digits is 816480, while the sum is 45.

The square root of 642739563 is about 25352.3088297693. The cubic root of 642739563 is about 863.0017526652.

The spelling of 642739563 in words is "six hundred forty-two million, seven hundred thirty-nine thousand, five hundred sixty-three".