215866020 has 96 divisors (see below), whose sum is σ = 638668800. Its totient is φ = 54391680.

The previous prime is 215866009. The next prime is 215866039. The reversal of 215866020 is 20668512.

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

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 78631 + ... + 81329.

It is an arithmetic number, because the mean of its divisors is an integer number (6652800).

Almost surely, 2^215866020 is an apocalyptic number.

215866020 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 215866020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (319334400).

215866020 is an abundant number, since it is smaller than the sum of its proper divisors (422802780).

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

215866020 is a wasteful number, since it uses less digits than its factorization.

215866020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2785 (or 2783 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 215866020 is about 14692.3796574959. The cubic root of 215866020 is about 599.8759187860.

The spelling of 215866020 in words is "two hundred fifteen million, eight hundred sixty-six thousand, twenty".