215916642 has 12 divisors (see below), whose sum is σ = 467819430. Its totient is φ = 71972208.

The previous prime is 215916641. The next prime is 215916653. The reversal of 215916642 is 246619512.

215916642 is a `hidden beast` number, since 2 + 1 + 5 + 9 + 1 + 6 + 642 = 666.

It can be written as a sum of positive squares in only one way, i.e., 206238321 + 9678321 = 14361^2 + 3111^2 .

It is a junction number, because it is equal to n+sod(n) for n = 215916597 and 215916606.

It is not an unprimeable number, because it can be changed into a prime (215916641) 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 5 ways as a sum of consecutive naturals, for example, 5997667 + ... + 5997702.

Almost surely, 2^215916642 is an apocalyptic number.

215916642 is an abundant number, since it is smaller than the sum of its proper divisors (251902788).

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

215916642 is a wasteful number, since it uses less digits than its factorization.

215916642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11995377 (or 11995374 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 215916642 is about 14694.1022862916. The cubic root of 215916642 is about 599.9228067358.

The spelling of 215916642 in words is "two hundred fifteen million, nine hundred sixteen thousand, six hundred forty-two".