215407920 has 240 divisors, whose sum is σ = 837133920. Its totient is φ = 45416448.

The previous prime is 215407859. The next prime is 215407939. The reversal of 215407920 is 29704512.

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 (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 152176 + ... + 153584.

It is an arithmetic number, because the mean of its divisors is an integer number (3488058).

Almost surely, 2^215407920 is an apocalyptic number.

215407920 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 215407920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (418566960).

215407920 is an abundant number, since it is smaller than the sum of its proper divisors (621726000).

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

215407920 is a wasteful number, since it uses less digits than its factorization.

215407920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1452 (or 1439 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 215407920 is about 14676.7816635664. The cubic root of 215407920 is about 599.4512761009.

The spelling of 215407920 in words is "two hundred fifteen million, four hundred seven thousand, nine hundred twenty".