385557691 has 2 divisors, whose sum is σ = 385557692. Its totient is φ = 385557690.

The previous prime is 385557677. The next prime is 385557719. The reversal of 385557691 is 196755583.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 385557691 - 2¹⁷ = 385426619 is a prime.

It is not a weakly prime, because it can be changed into another prime (385557611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 192778845 + 192778846.

It is an arithmetic number, because the mean of its divisors is an integer number (192778846).

Almost surely, 2^385557691 is an apocalyptic number.

385557691 is a deficient number, since it is larger than the sum of its proper divisors (1).

385557691 is an equidigital number, since it uses as much as digits as its factorization.

385557691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1134000, while the sum is 49.

The square root of 385557691 is about 19635.6230102332. The cubic root of 385557691 is about 727.8297279951.

The spelling of 385557691 in words is "three hundred eighty-five million, five hundred fifty-seven thousand, six hundred ninety-one".