57731220 has 72 divisors (see below), whose sum is σ = 177768864. Its totient is φ = 15162048.

The previous prime is 57731209. The next prime is 57731227. The reversal of 57731220 is 2213775.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (57731227) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9667 + ... + 14453.

It is an arithmetic number, because the mean of its divisors is an integer number (2469012).

Almost surely, 2^57731220 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 57731220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88884432).

57731220 is an abundant number, since it is smaller than the sum of its proper divisors (120037644).

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

57731220 is a wasteful number, since it uses less digits than its factorization.

57731220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4869 (or 4864 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 27.

The square root of 57731220 is about 7598.1063430305. The cubic root of 57731220 is about 386.4887988243.

Adding to 57731220 its reverse (2213775), we get a palindrome (59944995).

The spelling of 57731220 in words is "fifty-seven million, seven hundred thirty-one thousand, two hundred twenty".