399778283520 has 1152 divisors, whose sum is σ = 1762197353280. Its totient is φ = 82905661440.

The previous prime is 399778283519. The next prime is 399778283521. The reversal of 399778283520 is 25382877993.

399778283520 is a `hidden beast` number, since 39 + 9 + 7 + 78 + 2 + 8 + 3 + 520 = 666.

It is an interprime number because it is at equal distance from previous prime (399778283519) and next prime (399778283521).

It is a tau number, because it is divible by the number of its divisors (1152).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (399778283521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 794787589 + ... + 794788091.

Almost surely, 2^399778283520 is an apocalyptic number.

399778283520 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 399778283520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (881098676640).

399778283520 is an abundant number, since it is smaller than the sum of its proper divisors (1362419069760).

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

399778283520 is a wasteful number, since it uses less digits than its factorization.

399778283520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 569 (or 531 counting only the distinct ones).

The product of its (nonzero) digits is 45722880, while the sum is 63.

The spelling of 399778283520 in words is "three hundred ninety-nine billion, seven hundred seventy-eight million, two hundred eighty-three thousand, five hundred twenty".