398739032640 has 1344 divisors, whose sum is σ = 1644971950080. Its totient is φ = 90617978880.

The previous prime is 398739032639. The next prime is 398739032647. The reversal of 398739032640 is 46230937893.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398739032647) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 1041093889 + ... + 1041094271.

Almost surely, 2^398739032640 is an apocalyptic number.

398739032640 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 398739032640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (822485975040).

398739032640 is an abundant number, since it is smaller than the sum of its proper divisors (1246232917440).

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

398739032640 is a wasteful number, since it uses less digits than its factorization.

398739032640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 489 (or 460 counting only the distinct ones).

The product of its (nonzero) digits is 5878656, while the sum is 54.

It can be divided in two parts, 3987390 and 32640, that added together give a triangular number (4020030 = T₂₈₃₅).

The spelling of 398739032640 in words is "three hundred ninety-eight billion, seven hundred thirty-nine million, thirty-two thousand, six hundred forty".