399606557 has 4 divisors (see below), whose sum is σ = 456693216. Its totient is φ = 342519900.

The previous prime is 399606553. The next prime is 399606583. The reversal of 399606557 is 755606993.

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, and also an emirpimes, since its reverse is a distinct semiprime: 755606993 = 11677 ⋅64709.

It is a cyclic number.

It is not a de Polignac number, because 399606557 - 2² = 399606553 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399606553) 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, 28543319 + ... + 28543332.

It is an arithmetic number, because the mean of its divisors is an integer number (114173304).

Almost surely, 2^399606557 is an apocalyptic number.

It is an amenable number.

399606557 is a deficient number, since it is larger than the sum of its proper divisors (57086659).

399606557 is an equidigital number, since it uses as much as digits as its factorization.

399606557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57086658.

The product of its (nonzero) digits is 1530900, while the sum is 50.

The square root of 399606557 is about 19990.1615051005. The cubic root of 399606557 is about 736.5646444119.

The spelling of 399606557 in words is "three hundred ninety-nine million, six hundred six thousand, five hundred fifty-seven".