399475780 has 24 divisors (see below), whose sum is σ = 915163200. Its totient is φ = 145263840.

The previous prime is 399475771. The next prime is 399475789. The reversal of 399475780 is 87574993.

It is an interprime number because it is at equal distance from previous prime (399475771) and next prime (399475789).

It is not an unprimeable number, because it can be changed into a prime (399475789) 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, 907680 + ... + 908119.

It is an arithmetic number, because the mean of its divisors is an integer number (38131800).

Almost surely, 2^399475780 is an apocalyptic number.

It is an amenable number.

399475780 is an abundant number, since it is smaller than the sum of its proper divisors (515687420).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

399475780 is a wasteful number, since it uses less digits than its factorization.

399475780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1815819 (or 1815817 counting only the distinct ones).

The product of its (nonzero) digits is 1905120, while the sum is 52.

The square root of 399475780 is about 19986.8902033308. The cubic root of 399475780 is about 736.4842851830.

The spelling of 399475780 in words is "three hundred ninety-nine million, four hundred seventy-five thousand, seven hundred eighty".