191423857 has 2 divisors, whose sum is σ = 191423858. Its totient is φ = 191423856.

The previous prime is 191423851. The next prime is 191423887. The reversal of 191423857 is 758324191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 153859216 + 37564641 = 12404^2 + 6129^2 .

It is a cyclic number.

It is not a de Polignac number, because 191423857 - 2³ = 191423849 is a prime.

It is not a weakly prime, because it can be changed into another prime (191423851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95711928 + 95711929.

It is an arithmetic number, because the mean of its divisors is an integer number (95711929).

Almost surely, 2^191423857 is an apocalyptic number.

It is an amenable number.

191423857 is a deficient number, since it is larger than the sum of its proper divisors (1).

191423857 is an equidigital number, since it uses as much as digits as its factorization.

191423857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 40.

The square root of 191423857 is about 13835.6010711497. The cubic root of 191423857 is about 576.3222069210.

The spelling of 191423857 in words is "one hundred ninety-one million, four hundred twenty-three thousand, eight hundred fifty-seven".