221634144 has 120 divisors (see below), whose sum is σ = 669726288. Its totient is φ = 71850240.

The previous prime is 221634143. The next prime is 221634209. The reversal of 221634144 is 441436122.

It is a happy number.

221634144 is a `hidden beast` number, since 2 + 21 + 634 + 1 + 4 + 4 = 666.

It is a super-2 number, since 2×221634144² = 98243387573225472, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221634143) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 94749 + ... + 97059.

Almost surely, 2^221634144 is an apocalyptic number.

221634144 is a gapful number since it is divisible by the number (24) 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 221634144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (334863144).

221634144 is an abundant number, since it is smaller than the sum of its proper divisors (448092144).

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

221634144 is a wasteful number, since it uses less digits than its factorization.

221634144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2370 (or 2353 counting only the distinct ones).

The product of its digits is 4608, while the sum is 27.

The square root of 221634144 is about 14887.3820398349. The cubic root of 221634144 is about 605.1720877400.

The spelling of 221634144 in words is "two hundred twenty-one million, six hundred thirty-four thousand, one hundred forty-four".