215290400 has 144 divisors (see below), whose sum is σ = 573963264. Its totient is φ = 78382080.

The previous prime is 215290393. The next prime is 215290423. The reversal of 215290400 is 4092512.

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, 1320719 + ... + 1320881.

It is an arithmetic number, because the mean of its divisors is an integer number (3985856).

Almost surely, 2^215290400 is an apocalyptic number.

215290400 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 215290400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (286981632).

215290400 is an abundant number, since it is smaller than the sum of its proper divisors (358672864).

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

215290400 is a wasteful number, since it uses less digits than its factorization.

215290400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323 (or 310 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 215290400 is about 14672.7775148402. Note that the first 3 decimals coincide. The cubic root of 215290400 is about 599.3422421508.

The spelling of 215290400 in words is "two hundred fifteen million, two hundred ninety thousand, four hundred".