643612431 has 48 divisors (see below), whose sum is σ = 1083509504. Its totient is φ = 332640000.

The previous prime is 643612397. The next prime is 643612439. The reversal of 643612431 is 134216346.

It is not a de Polignac number, because 643612431 - 2⁷ = 643612303 is a prime.

It is a super-2 number, since 2×643612431² = 828473922675459522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643612439) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 611856 + ... + 612906.

Almost surely, 2^643612431 is an apocalyptic number.

643612431 is a deficient number, since it is larger than the sum of its proper divisors (439897073).

643612431 is a wasteful number, since it uses less digits than its factorization.

643612431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1324 (or 1313 counting only the distinct ones).

The product of its digits is 10368, while the sum is 30.

The square root of 643612431 is about 25369.5177526101. The cubic root of 643612431 is about 863.3922404644.

Adding to 643612431 its reverse (134216346), we get a palindrome (777828777).

The spelling of 643612431 in words is "six hundred forty-three million, six hundred twelve thousand, four hundred thirty-one".