399139453440 has 2560 divisors, whose sum is σ = 1900678348800. Its totient is φ = 77078200320.

The previous prime is 399139453421. The next prime is 399139453481. The reversal of 399139453440 is 44354931993.

399139453440 is a `hidden beast` number, since 3 + 9 + 9 + 13 + 94 + 534 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (2560).

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 4484712916 + ... + 4484713004.

It is an arithmetic number, because the mean of its divisors is an integer number (742452480).

Almost surely, 2^399139453440 is an apocalyptic number.

399139453440 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 399139453440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (950339174400).

399139453440 is an abundant number, since it is smaller than the sum of its proper divisors (1501538895360).

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

399139453440 is a wasteful number, since it uses less digits than its factorization.

399139453440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195 (or 173 counting only the distinct ones).

The product of its (nonzero) digits is 6298560, while the sum is 54.

The spelling of 399139453440 in words is "three hundred ninety-nine billion, one hundred thirty-nine million, four hundred fifty-three thousand, four hundred forty".