398640335040 has 336 divisors, whose sum is σ = 1435505879808. Its totient is φ = 101345789952.

The previous prime is 398640334993. The next prime is 398640335047. The reversal of 398640335040 is 40533046893.

398640335040 is a `hidden beast` number, since 39 + 86 + 4 + 0 + 33 + 504 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (398640335047) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 20325879 + ... + 20345481.

It is an arithmetic number, because the mean of its divisors is an integer number (4272338928).

Almost surely, 2^398640335040 is an apocalyptic number.

398640335040 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 398640335040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (717752939904).

398640335040 is an abundant number, since it is smaller than the sum of its proper divisors (1036865544768).

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

398640335040 is a wasteful number, since it uses less digits than its factorization.

398640335040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19956 (or 19943 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 45.

The spelling of 398640335040 in words is "three hundred ninety-eight billion, six hundred forty million, three hundred thirty-five thousand, forty".