57221216 has 48 divisors (see below), whose sum is σ = 123190704. Its totient is φ = 26002944.

The previous prime is 57221207. The next prime is 57221221. The reversal of 57221216 is 61212275.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26846 + ... + 28898.

It is an arithmetic number, because the mean of its divisors is an integer number (2566473).

Almost surely, 2^57221216 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 57221216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (61595352).

57221216 is an abundant number, since it is smaller than the sum of its proper divisors (65969488).

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

57221216 is a wasteful number, since it uses less digits than its factorization.

57221216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2143 (or 2135 counting only the distinct ones).

The product of its digits is 1680, while the sum is 26.

The square root of 57221216 is about 7564.4706358079. The cubic root of 57221216 is about 385.3473359561.

The spelling of 57221216 in words is "fifty-seven million, two hundred twenty-one thousand, two hundred sixteen".