215120400 has 240 divisors, whose sum is σ = 771260160. Its totient is φ = 50803200.

The previous prime is 215120369. The next prime is 215120401. The reversal of 215120400 is 4021512.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 215120400.

It is not an unprimeable number, because it can be changed into a prime (215120401) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 567411 + ... + 567789.

It is an arithmetic number, because the mean of its divisors is an integer number (3213584).

Almost surely, 2^215120400 is an apocalyptic number.

215120400 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 215120400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (385630080).

215120400 is an abundant number, since it is smaller than the sum of its proper divisors (556139760).

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

215120400 is a wasteful number, since it uses less digits than its factorization.

215120400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454 (or 443 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 215120400 is about 14666.9833299148. The cubic root of 215120400 is about 599.1844475147.

Adding to 215120400 its reverse (4021512), we get a palindrome (219141912).

The spelling of 215120400 in words is "two hundred fifteen million, one hundred twenty thousand, four hundred".