642518720634 has 16 divisors (see below), whose sum is σ = 1468614218688. Its totient is φ = 183576777312.

The previous prime is 642518720567. The next prime is 642518720639. The reversal of 642518720634 is 436027815246.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (642518720639) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7649032347 + ... + 7649032430.

It is an arithmetic number, because the mean of its divisors is an integer number (91788388668).

Almost surely, 2^642518720634 is an apocalyptic number.

642518720634 is an abundant number, since it is smaller than the sum of its proper divisors (826095498054).

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

642518720634 is a wasteful number, since it uses less digits than its factorization.

642518720634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15298064789.

The product of its (nonzero) digits is 1935360, while the sum is 48.

The spelling of 642518720634 in words is "six hundred forty-two billion, five hundred eighteen million, seven hundred twenty thousand, six hundred thirty-four".