394610521618 has 24 divisors (see below), whose sum is σ = 625517946828. Its totient is φ = 186678697248.

The previous prime is 394610521609. The next prime is 394610521619. The reversal of 394610521618 is 816125016493.

It can be written as a sum of positive squares in 2 ways, for example, as 342392330449 + 52218191169 = 585143^2 + 228513^2 .

It is not an unprimeable number, because it can be changed into a prime (394610521619) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 204580 + ... + 911632.

Almost surely, 2^394610521618 is an apocalyptic number.

394610521618 is a gapful number since it is divisible by the number (38) formed by its first and last digit.

394610521618 is a deficient number, since it is larger than the sum of its proper divisors (230907425210).

394610521618 is a wasteful number, since it uses less digits than its factorization.

394610521618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 707866 (or 707847 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 46.

The spelling of 394610521618 in words is "three hundred ninety-four billion, six hundred ten million, five hundred twenty-one thousand, six hundred eighteen".