394967618640 has 400 divisors, whose sum is σ = 1583929788672. Its totient is φ = 89346613248.

The previous prime is 394967618609. The next prime is 394967618671. The reversal of 394967618640 is 46816769493.

394967618640 is a `hidden beast` number, since 3 + 9 + 4 + 9 + 6 + 7 + 618 + 6 + 4 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (394967618609) and next prime (394967618671).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 4355037 + ... + 4444803.

Almost surely, 2^394967618640 is an apocalyptic number.

394967618640 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 394967618640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (791964894336).

394967618640 is an abundant number, since it is smaller than the sum of its proper divisors (1188962170032).

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

394967618640 is a wasteful number, since it uses less digits than its factorization.

394967618640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89896 (or 89881 counting only the distinct ones).

The product of its (nonzero) digits is 47029248, while the sum is 63.

The spelling of 394967618640 in words is "three hundred ninety-four billion, nine hundred sixty-seven million, six hundred eighteen thousand, six hundred forty".