399139280640 has 1008 divisors, whose sum is σ = 1544204390400. Its totient is φ = 98483724288.

The previous prime is 399139280633. The next prime is 399139280651. The reversal of 399139280640 is 46082931993.

399139280640 is a `hidden beast` number, since 39 + 91 + 392 + 80 + 64 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 833275921 + ... + 833276399.

It is an arithmetic number, because the mean of its divisors is an integer number (1531948800).

Almost surely, 2^399139280640 is an apocalyptic number.

399139280640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399139280640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (772102195200).

399139280640 is an abundant number, since it is smaller than the sum of its proper divisors (1145065109760).

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

399139280640 is an equidigital number, since it uses as much as digits as its factorization.

399139280640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 584 (or 555 counting only the distinct ones).

The product of its (nonzero) digits is 2519424, while the sum is 54.

The spelling of 399139280640 in words is "three hundred ninety-nine billion, one hundred thirty-nine million, two hundred eighty thousand, six hundred forty".