643517412 has 12 divisors (see below), whose sum is σ = 1501540656. Its totient is φ = 214505800.

The previous prime is 643517393. The next prime is 643517419. The reversal of 643517412 is 214715346.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×643517412² = 828229319094355488, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (643517419) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26813214 + ... + 26813237.

It is an arithmetic number, because the mean of its divisors is an integer number (125128388).

Almost surely, 2^643517412 is an apocalyptic number.

It is an amenable number.

643517412 is an abundant number, since it is smaller than the sum of its proper divisors (858023244).

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

643517412 is a wasteful number, since it uses less digits than its factorization.

643517412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53626458 (or 53626456 counting only the distinct ones).

The product of its digits is 20160, while the sum is 33.

The square root of 643517412 is about 25367.6449833247. The cubic root of 643517412 is about 863.3497497247.

The spelling of 643517412 in words is "six hundred forty-three million, five hundred seventeen thousand, four hundred twelve".