199157857 has 4 divisors (see below), whose sum is σ = 205582336. Its totient is φ = 192733380.

The previous prime is 199157837. The next prime is 199157887. The reversal of 199157857 is 758751991.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 199157857 - 2¹¹ = 199155809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (199157837) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3212193 + ... + 3212254.

It is an arithmetic number, because the mean of its divisors is an integer number (51395584).

Almost surely, 2^199157857 is an apocalyptic number.

It is an amenable number.

199157857 is a deficient number, since it is larger than the sum of its proper divisors (6424479).

199157857 is an equidigital number, since it uses as much as digits as its factorization.

199157857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6424478.

The product of its digits is 793800, while the sum is 52.

The square root of 199157857 is about 14112.3299635461. The cubic root of 199157857 is about 583.9815791791.

It can be divided in two parts, 19915 and 7857, that added together give a palindrome (27772).

The spelling of 199157857 in words is "one hundred ninety-nine million, one hundred fifty-seven thousand, eight hundred fifty-seven".