57001981 has 4 divisors (see below), whose sum is σ = 59480352. Its totient is φ = 54523612.

The previous prime is 57001949. The next prime is 57002039. The reversal of 57001981 is 18910075.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 57001981 - 2⁵ = 57001949 is a prime.

It is a super-2 number, since 2×57001981² = 6498451675848722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (57001181) 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, 1239151 + ... + 1239196.

It is an arithmetic number, because the mean of its divisors is an integer number (14870088).

Almost surely, 2^57001981 is an apocalyptic number.

It is an amenable number.

57001981 is a deficient number, since it is larger than the sum of its proper divisors (2478371).

57001981 is a wasteful number, since it uses less digits than its factorization.

57001981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2478370.

The product of its (nonzero) digits is 2520, while the sum is 31.

The square root of 57001981 is about 7549.9656290608. The cubic root of 57001981 is about 384.8545714858.

The spelling of 57001981 in words is "fifty-seven million, one thousand, nine hundred eighty-one".