642038961 has 4 divisors (see below), whose sum is σ = 856051952. Its totient is φ = 428025972.

The previous prime is 642038953. The next prime is 642038963. The reversal of 642038961 is 169830246.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 642038961 - 2³ = 642038953 is a prime.

It is a Duffinian number.

642038961 is a modest number, since divided by 38961 gives 642 as remainder.

It is not an unprimeable number, because it can be changed into a prime (642038963) 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, 107006491 + ... + 107006496.

It is an arithmetic number, because the mean of its divisors is an integer number (214012988).

Almost surely, 2^642038961 is an apocalyptic number.

It is an amenable number.

642038961 is a deficient number, since it is larger than the sum of its proper divisors (214012991).

642038961 is a wasteful number, since it uses less digits than its factorization.

642038961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214012990.

The product of its (nonzero) digits is 62208, while the sum is 39.

The square root of 642038961 is about 25338.4877409841. The cubic root of 642038961 is about 862.6880742560.

The spelling of 642038961 in words is "six hundred forty-two million, thirty-eight thousand, nine hundred sixty-one".