642651021331631 has 8 divisors (see below), whose sum is σ = 692087130952224. Its totient is φ = 593215113949920.

The previous prime is 642651021331609. The next prime is 642651021331639. The reversal of 642651021331631 is 136133120156246.

It is a happy number.

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 642651021331631 - 2³⁰ = 642649947589807 is a prime.

It is a super-3 number, since 3×642651021331631³ (a number of 45 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642651021331639) 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, 43927691 + ... + 56700476.

It is an arithmetic number, because the mean of its divisors is an integer number (86510891369028).

Almost surely, 2^{642651021331631} is an apocalyptic number.

642651021331631 is a deficient number, since it is larger than the sum of its proper divisors (49436109620593).

642651021331631 is a wasteful number, since it uses less digits than its factorization.

642651021331631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101119441.

The product of its (nonzero) digits is 466560, while the sum is 44.

Adding to 642651021331631 its reverse (136133120156246), we get a palindrome (778784141487877).

The spelling of 642651021331631 in words is "six hundred forty-two trillion, six hundred fifty-one billion, twenty-one million, three hundred thirty-one thousand, six hundred thirty-one".