398887815997440 has 4608 divisors, whose sum is σ = 1910793599769600. Its totient is φ = 77947081850880.

The previous prime is 398887815997397. The next prime is 398887815997481. The reversal of 398887815997440 is 44799518788893.

398887815997440 is a `hidden beast` number, since 3 + 9 + 8 + 8 + 8 + 7 + 8 + 1 + 599 + 7 + 4 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (4608).

It is a super-2 number, since 2×398887815997440² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (90).

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 322463876502 + ... + 322463877738.

It is an arithmetic number, because the mean of its divisors is an integer number (414668749950).

Almost surely, 2^{398887815997440} is an apocalyptic number.

398887815997440 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 398887815997440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (955396799884800).

398887815997440 is an abundant number, since it is smaller than the sum of its proper divisors (1511905783772160).

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

398887815997440 is a wasteful number, since it uses less digits than its factorization.

398887815997440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1331 (or 1282 counting only the distinct ones).

The product of its (nonzero) digits is 35115171840, while the sum is 90.

The spelling of 398887815997440 in words is "three hundred ninety-eight trillion, eight hundred eighty-seven billion, eight hundred fifteen million, nine hundred ninety-seven thousand, four hundred forty".