221649804 has 48 divisors (see below), whose sum is σ = 599639040. Its totient is φ = 70670160.

The previous prime is 221649739. The next prime is 221649809. The reversal of 221649804 is 408946122.

221649804 is a `hidden beast` number, since 2 + 2 + 1 + 649 + 8 + 0 + 4 = 666.

221649804 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×221649804² = 98257271226476832, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221649809) 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, 42132 + ... + 47099.

It is an arithmetic number, because the mean of its divisors is an integer number (12492480).

Almost surely, 2^221649804 is an apocalyptic number.

It is an amenable number.

221649804 is an abundant number, since it is smaller than the sum of its proper divisors (377989236).

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

221649804 is a wasteful number, since it uses less digits than its factorization.

221649804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89267 (or 89259 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 221649804 is about 14887.9079792965. The cubic root of 221649804 is about 605.1863406157.

The spelling of 221649804 in words is "two hundred twenty-one million, six hundred forty-nine thousand, eight hundred four".