399036181 has 2 divisors, whose sum is σ = 399036182. Its totient is φ = 399036180.

The previous prime is 399036167. The next prime is 399036199. The reversal of 399036181 is 181630993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 310957956 + 88078225 = 17634^2 + 9385^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-399036181 is a prime.

It is a super-2 number, since 2×399036181² = 318459747494129522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399036101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199518090 + 199518091.

It is an arithmetic number, because the mean of its divisors is an integer number (199518091).

Almost surely, 2^399036181 is an apocalyptic number.

It is an amenable number.

399036181 is a deficient number, since it is larger than the sum of its proper divisors (1).

399036181 is an equidigital number, since it uses as much as digits as its factorization.

399036181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34992, while the sum is 40.

The square root of 399036181 is about 19975.8899926887. The cubic root of 399036181 is about 736.2140338496.

The spelling of 399036181 in words is "three hundred ninety-nine million, thirty-six thousand, one hundred eighty-one".