212157639 has 12 divisors (see below), whose sum is σ = 307420776. Its totient is φ = 140990352.

The previous prime is 212157623. The next prime is 212157653. The reversal of 212157639 is 936751212.

212157639 is a `hidden beast` number, since 2 + 1 + 2 + 15 + 7 + 639 = 666.

It is not a de Polignac number, because 212157639 - 2⁴ = 212157623 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212157679) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 34329 + ... + 40034.

It is an arithmetic number, because the mean of its divisors is an integer number (25618398).

Almost surely, 2^212157639 is an apocalyptic number.

212157639 is a deficient number, since it is larger than the sum of its proper divisors (95263137).

212157639 is a wasteful number, since it uses less digits than its factorization.

212157639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74686 (or 74683 counting only the distinct ones).

The product of its digits is 22680, while the sum is 36.

The square root of 212157639 is about 14565.6321181060. The cubic root of 212157639 is about 596.4209514695.

The spelling of 212157639 in words is "two hundred twelve million, one hundred fifty-seven thousand, six hundred thirty-nine".