215815964 has 48 divisors (see below), whose sum is σ = 476204736. Its totient is φ = 83289600.

The previous prime is 215815961. The next prime is 215815973. The reversal of 215815964 is 469518512.

215815964 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215815961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7694 + ... + 22154.

It is an arithmetic number, because the mean of its divisors is an integer number (9920932).

Almost surely, 2^215815964 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 215815964, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (238102368).

215815964 is an abundant number, since it is smaller than the sum of its proper divisors (260388772).

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

215815964 is a wasteful number, since it uses less digits than its factorization.

215815964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14526 (or 14524 counting only the distinct ones).

The product of its digits is 86400, while the sum is 41.

The square root of 215815964 is about 14690.6760906365. The cubic root of 215815964 is about 599.8295478777.

The spelling of 215815964 in words is "two hundred fifteen million, eight hundred fifteen thousand, nine hundred sixty-four".