215255520 has 144 divisors (see below), whose sum is σ = 743822352. Its totient is φ = 56678400.

The previous prime is 215255471. The next prime is 215255531. The reversal of 215255520 is 25552512.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 118620 + ... + 120420.

It is an arithmetic number, because the mean of its divisors is an integer number (5165433).

Almost surely, 2^215255520 is an apocalyptic number.

215255520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 215255520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (371911176).

215255520 is an abundant number, since it is smaller than the sum of its proper divisors (528566832).

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

215255520 is a wasteful number, since it uses less digits than its factorization.

215255520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1905 (or 1894 counting only the distinct ones).

The product of its (nonzero) digits is 5000, while the sum is 27.

The square root of 215255520 is about 14671.5888710119. The cubic root of 215255520 is about 599.3098731793.

The spelling of 215255520 in words is "two hundred fifteen million, two hundred fifty-five thousand, five hundred twenty".