399999881 has 8 divisors (see below), whose sum is σ = 409284960. Its totient is φ = 390798432.

The previous prime is 399999869. The next prime is 399999893. The reversal of 399999881 is 188999993.

It is an interprime number because it is at equal distance from previous prime (399999869) and next prime (399999893).

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-399999881 is a prime.

It is a super-2 number, since 2×399999881² = 319999809600028322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (399999781) 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, 11180 + ... + 30413.

It is an arithmetic number, because the mean of its divisors is an integer number (51160620).

Almost surely, 2^399999881 is an apocalyptic number.

It is an amenable number.

399999881 is a deficient number, since it is larger than the sum of its proper divisors (9285079).

399999881 is a wasteful number, since it uses less digits than its factorization.

399999881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41815.

The product of its digits is 11337408, while the sum is 65.

The square root of 399999881 is about 19999.9970249998. The cubic root of 399999881 is about 736.8062266614.

The spelling of 399999881 in words is "three hundred ninety-nine million, nine hundred ninety-nine thousand, eight hundred eighty-one".