642636101251 has 8 divisors (see below), whose sum is σ = 680527857744. Its totient is φ = 604754304000.

The previous prime is 642636101227. The next prime is 642636101279. The reversal of 642636101251 is 152101636246.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 642636101251 - 2³¹ = 640488617603 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 642636101251.

It is not an unprimeable number, because it can be changed into a prime (642636191251) 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, 2356750 + ... + 2615251.

It is an arithmetic number, because the mean of its divisors is an integer number (85065982218).

Almost surely, 2^642636101251 is an apocalyptic number.

642636101251 is a deficient number, since it is larger than the sum of its proper divisors (37891756493).

642636101251 is a wasteful number, since it uses less digits than its factorization.

642636101251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4979621.

The product of its (nonzero) digits is 51840, while the sum is 37.

Adding to 642636101251 its reverse (152101636246), we get a palindrome (794737737497).

The spelling of 642636101251 in words is "six hundred forty-two billion, six hundred thirty-six million, one hundred one thousand, two hundred fifty-one".