212739640 has 32 divisors (see below), whose sum is σ = 491604480. Its totient is φ = 82795392.

The previous prime is 212739629. The next prime is 212739661. The reversal of 212739640 is 46937212.

It is a junction number, because it is equal to n+sod(n) for n = 212739596 and 212739605.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70392 + ... + 73351.

It is an arithmetic number, because the mean of its divisors is an integer number (15362640).

Almost surely, 2^212739640 is an apocalyptic number.

212739640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

212739640 is an abundant number, since it is smaller than the sum of its proper divisors (278864840).

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

212739640 is a wasteful number, since it uses less digits than its factorization.

212739640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143791 (or 143787 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 212739640 is about 14585.5970052652. The cubic root of 212739640 is about 596.9658303699.

The spelling of 212739640 in words is "two hundred twelve million, seven hundred thirty-nine thousand, six hundred forty".