642775051 has 4 divisors (see below), whose sum is σ = 657723352. Its totient is φ = 627826752.

The previous prime is 642775039. The next prime is 642775057. The reversal of 642775051 is 150577246.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642775051 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 642775051.

It is not an unprimeable number, because it can be changed into a prime (642775057) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7474086 + ... + 7474171.

It is an arithmetic number, because the mean of its divisors is an integer number (164430838).

Almost surely, 2^642775051 is an apocalyptic number.

642775051 is a deficient number, since it is larger than the sum of its proper divisors (14948301).

642775051 is a wasteful number, since it uses less digits than its factorization.

642775051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14948300.

The product of its (nonzero) digits is 58800, while the sum is 37.

The square root of 642775051 is about 25353.0087169156. The cubic root of 642775051 is about 863.0176355330.

The spelling of 642775051 in words is "six hundred forty-two million, seven hundred seventy-five thousand, fifty-one".