642068538 has 16 divisors (see below), whose sum is σ = 1286517216. Its totient is φ = 213626160.

The previous prime is 642068527. The next prime is 642068543. The reversal of 642068538 is 835860246.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 642068538.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 95656 + ... + 102147.

It is an arithmetic number, because the mean of its divisors is an integer number (80407326).

Almost surely, 2^642068538 is an apocalyptic number.

642068538 is an abundant number, since it is smaller than the sum of its proper divisors (644448678).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

642068538 is a wasteful number, since it uses less digits than its factorization.

642068538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198349.

The product of its (nonzero) digits is 276480, while the sum is 42.

The square root of 642068538 is about 25339.0713720925. The cubic root of 642068538 is about 862.7013212887.

It can be divided in two parts, 64 and 2068538, that added together give a palindrome (2068602).

The spelling of 642068538 in words is "six hundred forty-two million, sixty-eight thousand, five hundred thirty-eight".