215451660 has 48 divisors (see below), whose sum is σ = 605052000. Its totient is φ = 57283584.

The previous prime is 215451641. The next prime is 215451661. The reversal of 215451660 is 66154512.

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

It is not an unprimeable number, because it can be changed into a prime (215451661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15796 + ... + 26084.

It is an arithmetic number, because the mean of its divisors is an integer number (12605250).

Almost surely, 2^215451660 is an apocalyptic number.

215451660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215451660 is an abundant number, since it is smaller than the sum of its proper divisors (389600340).

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

215451660 is a wasteful number, since it uses less digits than its factorization.

215451660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10650 (or 10648 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 215451660 is about 14678.2716966270. The cubic root of 215451660 is about 599.4918475344.

The spelling of 215451660 in words is "two hundred fifteen million, four hundred fifty-one thousand, six hundred sixty".