212540640 has 96 divisors (see below), whose sum is σ = 721024416. Its totient is φ = 52316160.

The previous prime is 212540639. The next prime is 212540689. The reversal of 212540640 is 46045212.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 212540640.

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 15 ways as a sum of consecutive naturals, for example, 10791 + ... + 23270.

It is an arithmetic number, because the mean of its divisors is an integer number (7510671).

Almost surely, 2^212540640 is an apocalyptic number.

212540640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

212540640 is an abundant number, since it is smaller than the sum of its proper divisors (508483776).

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

212540640 is a wasteful number, since it uses less digits than its factorization.

212540640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34092 (or 34084 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 212540640 is about 14578.7736109729. The cubic root of 212540640 is about 596.7796352305.

Adding to 212540640 its reverse (46045212), we get a palindrome (258585852).

The spelling of 212540640 in words is "two hundred twelve million, five hundred forty thousand, six hundred forty".