199990457 has 4 divisors (see below), whose sum is σ = 202807296. Its totient is φ = 197173620.

The previous prime is 199990421. The next prime is 199990477. The reversal of 199990457 is 754099991.

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, and also an emirpimes, since its reverse is a distinct semiprime: 754099991 = 17 ⋅44358823.

It is a cyclic number.

It is not a de Polignac number, because 199990457 - 2¹⁸ = 199728313 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 199990399 and 199990408.

It is not an unprimeable number, because it can be changed into a prime (199990477) 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, 1408313 + ... + 1408454.

It is an arithmetic number, because the mean of its divisors is an integer number (50701824).

Almost surely, 2^199990457 is an apocalyptic number.

It is an amenable number.

199990457 is a deficient number, since it is larger than the sum of its proper divisors (2816839).

199990457 is an equidigital number, since it uses as much as digits as its factorization.

199990457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2816838.

The product of its (nonzero) digits is 918540, while the sum is 53.

The square root of 199990457 is about 14141.7982237055. The cubic root of 199990457 is about 584.7942461942.

The spelling of 199990457 in words is "one hundred ninety-nine million, nine hundred ninety thousand, four hundred fifty-seven".