212991732 has 18 divisors (see below), whose sum is σ = 538395858. Its totient is φ = 70997232.

The previous prime is 212991697. The next prime is 212991749. The reversal of 212991732 is 237199212.

212991732 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 157101156 + 55890576 = 12534^2 + 7476^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 5916437 = 212991732 / (2 + 1 + 2 + 9 + 9 + 1 + 7 + 3 + 2).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2958183 + ... + 2958254.

It is an arithmetic number, because the mean of its divisors is an integer number (29910881).

Almost surely, 2^212991732 is an apocalyptic number.

It is an amenable number.

212991732 is an abundant number, since it is smaller than the sum of its proper divisors (325404126).

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

212991732 is a wasteful number, since it uses less digits than its factorization.

212991732 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5916447 (or 5916442 counting only the distinct ones).

The product of its digits is 13608, while the sum is 36.

The square root of 212991732 is about 14594.2362595649. The cubic root of 212991732 is about 597.2015346116.

The spelling of 212991732 in words is "two hundred twelve million, nine hundred ninety-one thousand, seven hundred thirty-two".