642562991 has 32 divisors (see below), whose sum is σ = 801073152. Its totient is φ = 502894080.

The previous prime is 642562969. The next prime is 642563023. The reversal of 642562991 is 199265246.

It is a cyclic number.

It is not a de Polignac number, because 642562991 - 2¹⁰ = 642561967 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642562901) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 732245 + ... + 733121.

It is an arithmetic number, because the mean of its divisors is an integer number (25033536).

Almost surely, 2^642562991 is an apocalyptic number.

642562991 is a deficient number, since it is larger than the sum of its proper divisors (158510161).

642562991 is a wasteful number, since it uses less digits than its factorization.

642562991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1079.

The product of its digits is 233280, while the sum is 44.

The square root of 642562991 is about 25348.8262252910. The cubic root of 642562991 is about 862.9227181125.

The spelling of 642562991 in words is "six hundred forty-two million, five hundred sixty-two thousand, nine hundred ninety-one".