19857157 has 2 divisors, whose sum is σ = 19857158. Its totient is φ = 19857156.

The previous prime is 19857133. The next prime is 19857179. The reversal of 19857157 is 75175891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15992001 + 3865156 = 3999^2 + 1966^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19857157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19857127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9928578 + 9928579.

It is an arithmetic number, because the mean of its divisors is an integer number (9928579).

Almost surely, 2^19857157 is an apocalyptic number.

It is an amenable number.

19857157 is a deficient number, since it is larger than the sum of its proper divisors (1).

19857157 is an equidigital number, since it uses as much as digits as its factorization.

19857157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 88200, while the sum is 43.

The square root of 19857157 is about 4456.1370041775. The cubic root of 19857157 is about 270.7939911189.

The spelling of 19857157 in words is "nineteen million, eight hundred fifty-seven thousand, one hundred fifty-seven".