399647053440 has 768 divisors, whose sum is σ = 1472318265600. Its totient is φ = 103553925120.

The previous prime is 399647053391. The next prime is 399647053441. The reversal of 399647053440 is 44350746993.

It is a happy number.

399647053440 is a `hidden beast` number, since 3 + 9 + 9 + 64 + 7 + 0 + 534 + 40 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (399647053441) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 977131956 + ... + 977132364.

It is an arithmetic number, because the mean of its divisors is an integer number (1917081075).

Almost surely, 2^399647053440 is an apocalyptic number.

399647053440 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 399647053440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (736159132800).

399647053440 is an abundant number, since it is smaller than the sum of its proper divisors (1072671212160).

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

399647053440 is a wasteful number, since it uses less digits than its factorization.

399647053440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 607 (or 583 counting only the distinct ones).

The product of its (nonzero) digits is 9797760, while the sum is 54.

The spelling of 399647053440 in words is "three hundred ninety-nine billion, six hundred forty-seven million, fifty-three thousand, four hundred forty".