394736640 has 176 divisors, whose sum is σ = 1304839680. Its totient is φ = 101744640.

The previous prime is 394736621. The next prime is 394736653. The reversal of 394736640 is 46637493.

It is a junction number, because it is equal to n+sod(n) for n = 394736592 and 394736601.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 475746 + ... + 476574.

Almost surely, 2^394736640 is an apocalyptic number.

394736640 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 394736640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (652419840).

394736640 is an abundant number, since it is smaller than the sum of its proper divisors (910103040).

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

394736640 is a wasteful number, since it uses less digits than its factorization.

394736640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 888 (or 870 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 42.

The square root of 394736640 is about 19867.9802697708. The cubic root of 394736640 is about 733.5602897162.

The spelling of 394736640 in words is "three hundred ninety-four million, seven hundred thirty-six thousand, six hundred forty".