57891781 has 2 divisors, whose sum is σ = 57891782. Its totient is φ = 57891780.

The previous prime is 57891761. The next prime is 57891793. The reversal of 57891781 is 18719875.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43678881 + 14212900 = 6609^2 + 3770^2 .

It is a cyclic number.

It is not a de Polignac number, because 57891781 - 2⁷ = 57891653 is a prime.

It is a super-2 number, since 2×57891781² = 6702916614703922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (57891751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28945890 + 28945891.

It is an arithmetic number, because the mean of its divisors is an integer number (28945891).

Almost surely, 2^57891781 is an apocalyptic number.

It is an amenable number.

57891781 is a deficient number, since it is larger than the sum of its proper divisors (1).

57891781 is an equidigital number, since it uses as much as digits as its factorization.

57891781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 141120, while the sum is 46.

The square root of 57891781 is about 7608.6648631675. The cubic root of 57891781 is about 386.8467656690.

The spelling of 57891781 in words is "fifty-seven million, eight hundred ninety-one thousand, seven hundred eighty-one".