212639640 has 64 divisors (see below), whose sum is σ = 671500800. Its totient is φ = 53718912.

The previous prime is 212639579. The next prime is 212639677. The reversal of 212639640 is 46936212.

212639640 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44352 + ... + 48911.

It is an arithmetic number, because the mean of its divisors is an integer number (10492200).

Almost surely, 2^212639640 is an apocalyptic number.

212639640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

212639640 is an abundant number, since it is smaller than the sum of its proper divisors (458861160).

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

212639640 is a wasteful number, since it uses less digits than its factorization.

212639640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93296 (or 93292 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 33.

The square root of 212639640 is about 14582.1685630087. The cubic root of 212639640 is about 596.8722794938.

It can be divided in two parts, 21263 and 9640, that added together give a palindrome (30903).

The spelling of 212639640 in words is "two hundred twelve million, six hundred thirty-nine thousand, six hundred forty".