1640668404 has 12 divisors (see below), whose sum is σ = 3828226304. Its totient is φ = 546889464.

The previous prime is 1640668399. The next prime is 1640668441. The reversal of 1640668404 is 4048660461.

1640668404 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68361172 + ... + 68361195.

Almost surely, 2^1640668404 is an apocalyptic number.

It is an amenable number.

1640668404 is an abundant number, since it is smaller than the sum of its proper divisors (2187557900).

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

1640668404 is a wasteful number, since it uses less digits than its factorization.

1640668404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136722374 (or 136722372 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 39.

The square root of 1640668404 is about 40505.1651521136. The cubic root of 1640668404 is about 1179.4338958402.

The spelling of 1640668404 in words is "one billion, six hundred forty million, six hundred sixty-eight thousand, four hundred four".