215378920 has 32 divisors (see below), whose sum is σ = 486208800. Its totient is φ = 85866048.

The previous prime is 215378893. The next prime is 215378921. The reversal of 215378920 is 29873512.

It is a self number, because there is not a number n which added to its sum of digits gives 215378920.

It is not an unprimeable number, because it can be changed into a prime (215378921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3511 + ... + 21049.

It is an arithmetic number, because the mean of its divisors is an integer number (15194025).

Almost surely, 2^215378920 is an apocalyptic number.

215378920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215378920 is an abundant number, since it is smaller than the sum of its proper divisors (270829880).

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

215378920 is a wasteful number, since it uses less digits than its factorization.

215378920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17857 (or 17853 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 37.

The square root of 215378920 is about 14675.7936753008. The cubic root of 215378920 is about 599.4243738601.

The spelling of 215378920 in words is "two hundred fifteen million, three hundred seventy-eight thousand, nine hundred twenty".