398095064640 has 672 divisors, whose sum is σ = 1705666749696. Its totient is φ = 82977177600.

The previous prime is 398095064639. The next prime is 398095064651. The reversal of 398095064640 is 46460590893.

398095064640 is a `hidden beast` number, since 3 + 98 + 0 + 9 + 506 + 4 + 6 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 21743490 + ... + 21761790.

It is an arithmetic number, because the mean of its divisors is an integer number (2538194568).

Almost surely, 2^398095064640 is an apocalyptic number.

398095064640 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 398095064640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (852833374848).

398095064640 is an abundant number, since it is smaller than the sum of its proper divisors (1307571685056).

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

398095064640 is a wasteful number, since it uses less digits than its factorization.

398095064640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18427 (or 18414 counting only the distinct ones).

The product of its (nonzero) digits is 5598720, while the sum is 54.

It can be divided in two parts, 3980950 and 64640, that added together give a triangular number (4045590 = T₂₈₄₄).

The spelling of 398095064640 in words is "three hundred ninety-eight billion, ninety-five million, sixty-four thousand, six hundred forty".