57217840 has 20 divisors (see below), whose sum is σ = 133031664. Its totient is φ = 22887104.

The previous prime is 57217829. The next prime is 57217843. The reversal of 57217840 is 4871275.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 57217796 and 57217805.

It is not an unprimeable number, because it can be changed into a prime (57217843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 357532 + ... + 357691.

Almost surely, 2^57217840 is an apocalyptic number.

It is an amenable number.

57217840 is an abundant number, since it is smaller than the sum of its proper divisors (75813824).

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

57217840 is a wasteful number, since it uses less digits than its factorization.

57217840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 715236 (or 715230 counting only the distinct ones).

The product of its (nonzero) digits is 15680, while the sum is 34.

The square root of 57217840 is about 7564.2474840529. The cubic root of 57217840 is about 385.3397574256.

The spelling of 57217840 in words is "fifty-seven million, two hundred seventeen thousand, eight hundred forty".