199439901 has 20 divisors (see below), whose sum is σ = 303556572. Its totient is φ = 130448448.

The previous prime is 199439897. The next prime is 199439921. The reversal of 199439901 is 109934991.

It can be written as a sum of positive squares in 2 ways, for example, as 156275001 + 43164900 = 12501^2 + 6570^2 .

It is not a de Polignac number, because 199439901 - 2² = 199439897 is a prime.

It is a super-2 number, since 2×199439901² = 79552548221779602, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199439921) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 18936 + ... + 27521.

Almost surely, 2^199439901 is an apocalyptic number.

It is an amenable number.

199439901 is a deficient number, since it is larger than the sum of its proper divisors (104116671).

199439901 is an equidigital number, since it uses as much as digits as its factorization.

199439901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46522 (or 46513 counting only the distinct ones).

The product of its (nonzero) digits is 78732, while the sum is 45.

The square root of 199439901 is about 14122.3192500382. The cubic root of 199439901 is about 584.2571241022.

The spelling of 199439901 in words is "one hundred ninety-nine million, four hundred thirty-nine thousand, nine hundred one".