215972838 has 16 divisors (see below), whose sum is σ = 479939760. Its totient is φ = 71990928.

The previous prime is 215972833. The next prime is 215972839. The reversal of 215972838 is 838279512.

It is a happy number.

215972838 is a `hidden beast` number, since 2 + 1 + 597 + 28 + 38 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 215972793 and 215972802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215972833) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1999695 + ... + 1999802.

It is an arithmetic number, because the mean of its divisors is an integer number (29996235).

Almost surely, 2^215972838 is an apocalyptic number.

215972838 is an abundant number, since it is smaller than the sum of its proper divisors (263966922).

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

215972838 is a wasteful number, since it uses less digits than its factorization.

215972838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3999508 (or 3999502 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The square root of 215972838 is about 14696.0143576413. The cubic root of 215972838 is about 599.9748489457.

The spelling of 215972838 in words is "two hundred fifteen million, nine hundred seventy-two thousand, eight hundred thirty-eight".