642130642 has 4 divisors (see below), whose sum is σ = 963195966. Its totient is φ = 321065320.

The previous prime is 642130633. The next prime is 642130661. The reversal of 642130642 is 246031246.

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

It can be written as a sum of positive squares in only one way, i.e., 495018001 + 147112641 = 22249^2 + 12129^2 .

It is a super-2 number, since 2×642130642² = 824663522790664328, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 642130642.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160532659 + ... + 160532662.

Almost surely, 2^642130642 is an apocalyptic number.

642130642 is a deficient number, since it is larger than the sum of its proper divisors (321065324).

642130642 is a wasteful number, since it uses less digits than its factorization.

642130642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321065323.

The product of its (nonzero) digits is 6912, while the sum is 28.

The square root of 642130642 is about 25340.2968017346. The cubic root of 642130642 is about 862.7291352849.

Adding to 642130642 its reverse (246031246), we get a palindrome (888161888).

The spelling of 642130642 in words is "six hundred forty-two million, one hundred thirty thousand, six hundred forty-two".