399102661 has 4 divisors (see below), whose sum is σ = 399171712. Its totient is φ = 399033612.

The previous prime is 399102631. The next prime is 399102677. The reversal of 399102661 is 166201993.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 399102661 - 2⁷ = 399102533 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 399102661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399102631) 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, 24975 + ... + 37708.

It is an arithmetic number, because the mean of its divisors is an integer number (99792928).

Almost surely, 2^399102661 is an apocalyptic number.

It is an amenable number.

399102661 is a deficient number, since it is larger than the sum of its proper divisors (69051).

399102661 is an equidigital number, since it uses as much as digits as its factorization.

399102661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69050.

The product of its (nonzero) digits is 17496, while the sum is 37.

The square root of 399102661 is about 19977.5539293478. The cubic root of 399102661 is about 736.2549163506.

The spelling of 399102661 in words is "three hundred ninety-nine million, one hundred two thousand, six hundred sixty-one".