642050721 has 24 divisors (see below), whose sum is σ = 1002770496. Its totient is φ = 393516000.

The previous prime is 642050707. The next prime is 642050737. The reversal of 642050721 is 127050246.

It is not a de Polignac number, because 642050721 - 2⁹ = 642050209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (642050701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18436 + ... + 40298.

It is an arithmetic number, because the mean of its divisors is an integer number (41782104).

Almost surely, 2^642050721 is an apocalyptic number.

It is an amenable number.

642050721 is a deficient number, since it is larger than the sum of its proper divisors (360719775).

642050721 is a wasteful number, since it uses less digits than its factorization.

642050721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22133 (or 22130 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 642050721 is about 25338.7197979693. The cubic root of 642050721 is about 862.6933414077.

The spelling of 642050721 in words is "six hundred forty-two million, fifty thousand, seven hundred twenty-one".