399777 has 8 divisors (see below), whose sum is σ = 609216. Its totient is φ = 228432.

The previous prime is 399769. The next prime is 399781. The reversal of 399777 is 777993.

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

It is not a de Polignac number, because 399777 - 2³ = 399769 is a prime.

399777 is a modest number, since divided by 777 gives 399 as remainder.

It is not an unprimeable number, because it can be changed into a prime (399727) 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, 9498 + ... + 9539.

It is an arithmetic number, because the mean of its divisors is an integer number (76152).

2³⁹⁹⁷⁷⁷ is an apocalyptic number.

It is an amenable number.

399777 is a deficient number, since it is larger than the sum of its proper divisors (209439).

399777 is a wasteful number, since it uses less digits than its factorization.

399777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19047.

The product of its digits is 83349, while the sum is 42.

The square root of 399777 is about 632.2792104759. The cubic root of 399777 is about 73.6669351105. Note that the first 3 decimals are identical.

It can be divided in two parts, 399 and 777, that added together give a triangular number (1176 = T₄₈).

The spelling of 399777 in words is "three hundred ninety-nine thousand, seven hundred seventy-seven".