221971392 has 84 divisors (see below), whose sum is σ = 645078720. Its totient is φ = 72963072.

The previous prime is 221971381. The next prime is 221971403. The reversal of 221971392 is 293179122.

It is an interprime number because it is at equal distance from previous prime (221971381) and next prime (221971403).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39409 + ... + 44687.

Almost surely, 2^221971392 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221971392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (322539360).

221971392 is an abundant number, since it is smaller than the sum of its proper divisors (423107328).

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

221971392 is a wasteful number, since it uses less digits than its factorization.

221971392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5370 (or 5357 counting only the distinct ones).

The product of its digits is 13608, while the sum is 36.

The square root of 221971392 is about 14898.7043731997. The cubic root of 221971392 is about 605.4788840983.

The spelling of 221971392 in words is "two hundred twenty-one million, nine hundred seventy-one thousand, three hundred ninety-two".