643630012531 has 8 divisors (see below), whose sum is σ = 702148312944. Its totient is φ = 585112792320.

The previous prime is 643630012511. The next prime is 643630012537. The reversal of 643630012531 is 135210036346.

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 643630012531 - 2¹⁵ = 643629979763 is a prime.

It is a super-2 number, since 2×643630012531² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643630012537) 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, 1454875 + ... + 1844971.

It is an arithmetic number, because the mean of its divisors is an integer number (87768539118).

Almost surely, 2^643630012531 is an apocalyptic number.

643630012531 is a deficient number, since it is larger than the sum of its proper divisors (58518300413).

643630012531 is a wasteful number, since it uses less digits than its factorization.

643630012531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 540101.

The product of its (nonzero) digits is 38880, while the sum is 34.

Adding to 643630012531 its reverse (135210036346), we get a palindrome (778840048877).

The spelling of 643630012531 in words is "six hundred forty-three billion, six hundred thirty million, twelve thousand, five hundred thirty-one".