199690121 has 4 divisors (see below), whose sum is σ = 200401044. Its totient is φ = 198979200.

The previous prime is 199690093. The next prime is 199690129. The reversal of 199690121 is 121096991.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 171217225 + 28472896 = 13085^2 + 5336^2 .

It is a cyclic number.

It is not a de Polignac number, because 199690121 - 2²⁶ = 132581257 is a prime.

It is a super-2 number, since 2×199690121² = 79752288849989282, which contains 22 as substring.

It is a pancake number, because a pancake can be divided into 199690121 parts by 19984 straight cuts.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (199690129) 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, 355040 + ... + 355601.

It is an arithmetic number, because the mean of its divisors is an integer number (50100261).

Almost surely, 2^199690121 is an apocalyptic number.

It is an amenable number.

199690121 is a deficient number, since it is larger than the sum of its proper divisors (710923).

199690121 is an equidigital number, since it uses as much as digits as its factorization.

199690121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710922.

The product of its (nonzero) digits is 8748, while the sum is 38.

The square root of 199690121 is about 14131.1754995825. The cubic root of 199690121 is about 584.5013609557.

The spelling of 199690121 in words is "one hundred ninety-nine million, six hundred ninety thousand, one hundred twenty-one".