221610144 has 72 divisors (see below), whose sum is σ = 676716768. Its totient is φ = 63315840.

The previous prime is 221610143. The next prime is 221610157. The reversal of 221610144 is 441016122.

It is a happy number.

It is a super-2 number, since 2×221610144² = 98222111847401472, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 221610144.

It is not an unprimeable number, because it can be changed into a prime (221610143) 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, 18852 + ... + 28259.

It is an arithmetic number, because the mean of its divisors is an integer number (9398844).

Almost surely, 2^221610144 is an apocalyptic number.

221610144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

221610144 is an abundant number, since it is smaller than the sum of its proper divisors (455106624).

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

221610144 is a wasteful number, since it uses less digits than its factorization.

221610144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47138 (or 47123 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 221610144 is about 14886.5759662859. The cubic root of 221610144 is about 605.1502429494.

Adding to 221610144 its reverse (441016122), we get a palindrome (662626266).

The spelling of 221610144 in words is "two hundred twenty-one million, six hundred ten thousand, one hundred forty-four".