643931374 has 16 divisors (see below), whose sum is σ = 972937728. Its totient is φ = 319627872.

The previous prime is 643931359. The next prime is 643931377. The reversal of 643931374 is 473139346.

It is a happy number.

It is a super-2 number, since 2×643931374² = 829295228843055752, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643931377) 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, 160339 + ... + 164305.

It is an arithmetic number, because the mean of its divisors is an integer number (60808608).

Almost surely, 2^643931374 is an apocalyptic number.

643931374 is a deficient number, since it is larger than the sum of its proper divisors (329006354).

643931374 is a wasteful number, since it uses less digits than its factorization.

643931374 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4539.

The product of its digits is 163296, while the sum is 40.

The square root of 643931374 is about 25375.8029232574. The cubic root of 643931374 is about 863.5348353054.

The spelling of 643931374 in words is "six hundred forty-three million, nine hundred thirty-one thousand, three hundred seventy-four".