215406660 has 96 divisors (see below), whose sum is σ = 729872640. Its totient is φ = 46338048.

The previous prime is 215406647. The next prime is 215406673. The reversal of 215406660 is 66604512.

It is an interprime number because it is at equal distance from previous prime (215406647) and next prime (215406673).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7945 + ... + 22224.

It is an arithmetic number, because the mean of its divisors is an integer number (7602840).

Almost surely, 2^215406660 is an apocalyptic number.

215406660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215406660 is an abundant number, since it is smaller than the sum of its proper divisors (514465980).

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

215406660 is a wasteful number, since it uses less digits than its factorization.

215406660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30205 (or 30203 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 215406660 is about 14676.7387385618. The cubic root of 215406660 is about 599.4501072951.

The spelling of 215406660 in words is "two hundred fifteen million, four hundred six thousand, six hundred sixty".