399961943040 has 528 divisors, whose sum is σ = 1482650025984. Its totient is φ = 91245772800.

The previous prime is 399961943033. The next prime is 399961943041. The reversal of 399961943040 is 40349169993.

It is a tau number, because it is divible by the number of its divisors (528).

It is not an unprimeable number, because it can be changed into a prime (399961943041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 48825345 + ... + 48833535.

Almost surely, 2^399961943040 is an apocalyptic number.

399961943040 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 399961943040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (741325012992).

399961943040 is an abundant number, since it is smaller than the sum of its proper divisors (1082688082944).

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

399961943040 is a wasteful number, since it uses less digits than its factorization.

399961943040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8264 (or 8229 counting only the distinct ones).

The product of its (nonzero) digits is 5668704, while the sum is 57.

It can be divided in two parts, 39996 and 1943040, that added together give a triangular number (1983036 = T₁₉₉₁).

The spelling of 399961943040 in words is "three hundred ninety-nine billion, nine hundred sixty-one million, nine hundred forty-three thousand, forty".