399800026 has 4 divisors (see below), whose sum is σ = 599700042. Its totient is φ = 199900012.

The previous prime is 399799997. The next prime is 399800047. The reversal of 399800026 is 620008993.

It is a Cunningham number, because it is equal to 19995²+1.

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

It can be written as a sum of positive squares in only one way, i.e., 399800025 + 1 = 19995^2 + 1^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99950005 + ... + 99950008.

Almost surely, 2^399800026 is an apocalyptic number.

399800026 is a deficient number, since it is larger than the sum of its proper divisors (199900016).

399800026 is a wasteful number, since it uses less digits than its factorization.

399800026 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199900015.

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 399800026 is about 19995.0000250063. Note that the first 4 decimals coincide. The cubic root of 399800026 is about 736.6834941751.

The spelling of 399800026 in words is "three hundred ninety-nine million, eight hundred thousand, twenty-six".