221423872 has 36 divisors (see below), whose sum is σ = 465255280. Its totient is φ = 104882688.

The previous prime is 221423869. The next prime is 221423879. The reversal of 221423872 is 278324122.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (221423879) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17898 + ... + 27625.

Almost surely, 2^221423872 is an apocalyptic number.

It is an amenable number.

221423872 is an abundant number, since it is smaller than the sum of its proper divisors (243831408).

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

221423872 is an equidigital number, since it uses as much as digits as its factorization.

221423872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45558 (or 45544 counting only the distinct ones).

The product of its digits is 10752, while the sum is 31.

The square root of 221423872 is about 14880.3182761660. The cubic root of 221423872 is about 604.9806446008.

Adding to 221423872 its reverse (278324122), we get a palindrome (499747994).

The spelling of 221423872 in words is "two hundred twenty-one million, four hundred twenty-three thousand, eight hundred seventy-two".