394610521640 has 16 divisors (see below), whose sum is σ = 887873673780. Its totient is φ = 157844208640.

The previous prime is 394610521619. The next prime is 394610521649. The reversal of 394610521640 is 46125016493.

It can be written as a sum of positive squares in 2 ways, for example, as 365374309444 + 29236212196 = 604462^2 + 170986^2 .

It is not an unprimeable number, because it can be changed into a prime (394610521649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4932631481 + ... + 4932631560.

Almost surely, 2^394610521640 is an apocalyptic number.

It is an amenable number.

394610521640 is an abundant number, since it is smaller than the sum of its proper divisors (493263152140).

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

394610521640 is a wasteful number, since it uses less digits than its factorization.

394610521640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9865263052 (or 9865263048 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 41.

The spelling of 394610521640 in words is "three hundred ninety-four billion, six hundred ten million, five hundred twenty-one thousand, six hundred forty".