399775681 has 8 divisors (see below), whose sum is σ = 407484000. Its totient is φ = 392098560.

The previous prime is 399775657. The next prime is 399775709. The reversal of 399775681 is 186577993.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 399775681 - 2⁹ = 399775169 is a prime.

It is a super-2 number, since 2×399775681² = 319641190238027522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399775631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18946 + ... + 34036.

It is an arithmetic number, because the mean of its divisors is an integer number (50935500).

Almost surely, 2^399775681 is an apocalyptic number.

It is an amenable number.

399775681 is a deficient number, since it is larger than the sum of its proper divisors (7708319).

399775681 is a wasteful number, since it uses less digits than its factorization.

399775681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15599.

The product of its digits is 2857680, while the sum is 55.

The square root of 399775681 is about 19994.3912385449. The cubic root of 399775681 is about 736.6685409296.

The spelling of 399775681 in words is "three hundred ninety-nine million, seven hundred seventy-five thousand, six hundred eighty-one".