57191861 has 2 divisors, whose sum is σ = 57191862. Its totient is φ = 57191860.

The previous prime is 57191851. The next prime is 57191863. The reversal of 57191861 is 16819175.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42706225 + 14485636 = 6535^2 + 3806^2 .

It is a cyclic number.

It is not a de Polignac number, because 57191861 - 2²² = 52997557 is a prime.

Together with 57191863, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (57191863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28595930 + 28595931.

It is an arithmetic number, because the mean of its divisors is an integer number (28595931).

Almost surely, 2^57191861 is an apocalyptic number.

It is an amenable number.

57191861 is a deficient number, since it is larger than the sum of its proper divisors (1).

57191861 is an equidigital number, since it uses as much as digits as its factorization.

57191861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15120, while the sum is 38.

The square root of 57191861 is about 7562.5300660559. The cubic root of 57191861 is about 385.2814291314.

The spelling of 57191861 in words is "fifty-seven million, one hundred ninety-one thousand, eight hundred sixty-one".