399761 has 2 divisors, whose sum is σ = 399762. Its totient is φ = 399760.

The previous prime is 399757. The next prime is 399769. The reversal of 399761 is 167993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 398161 + 1600 = 631^2 + 40^2 .

It is a cyclic number.

It is not a de Polignac number, because 399761 - 2² = 399757 is a prime.

It is a Sophie Germain prime.

It is an Ulam number.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (399769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199880 + 199881.

It is an arithmetic number, because the mean of its divisors is an integer number (199881).

2³⁹⁹⁷⁶¹ is an apocalyptic number.

It is an amenable number.

399761 is a deficient number, since it is larger than the sum of its proper divisors (1).

399761 is an equidigital number, since it uses as much as digits as its factorization.

399761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10206, while the sum is 35.

The square root of 399761 is about 632.2665577112. The cubic root of 399761 is about 73.6659523237.

The spelling of 399761 in words is "three hundred ninety-nine thousand, seven hundred sixty-one".