215189856 has 144 divisors (see below), whose sum is σ = 704549664. Its totient is φ = 61028352.

The previous prime is 215189803. The next prime is 215189857. The reversal of 215189856 is 658981512.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215189857) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 348460 + ... + 349076.

It is an arithmetic number, because the mean of its divisors is an integer number (4892706).

Almost surely, 2^215189856 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 215189856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (352274832).

215189856 is an abundant number, since it is smaller than the sum of its proper divisors (489359808).

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

215189856 is a wasteful number, since it uses less digits than its factorization.

215189856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 813 (or 802 counting only the distinct ones).

The product of its digits is 172800, while the sum is 45.

The square root of 215189856 is about 14669.3509058854. The cubic root of 215189856 is about 599.2489268742.

The spelling of 215189856 in words is "two hundred fifteen million, one hundred eighty-nine thousand, eight hundred fifty-six".