218949660 has 36 divisors (see below), whose sum is σ = 664147848. Its totient is φ = 58386528.

The previous prime is 218949659. The next prime is 218949667. The reversal of 218949660 is 66949812.

It is a happy number.

218949660 is a `hidden beast` number, since 21 + 89 + 496 + 60 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×218949660² = 95877907228231200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218949667) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 608014 + ... + 608373.

Almost surely, 2^218949660 is an apocalyptic number.

218949660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

218949660 is an abundant number, since it is smaller than the sum of its proper divisors (445198188).

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

218949660 is a wasteful number, since it uses less digits than its factorization.

218949660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1216402 (or 1216397 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The square root of 218949660 is about 14796.9476582165. The cubic root of 218949660 is about 602.7188280148.

The spelling of 218949660 in words is "two hundred eighteen million, nine hundred forty-nine thousand, six hundred sixty".