1645993668 has 24 divisors (see below), whose sum is σ = 4189802400. Its totient is φ = 498785920.

The previous prime is 1645993651. The next prime is 1645993681. The reversal of 1645993668 is 8663995461.

1645993668 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6234693 + ... + 6234956.

It is an arithmetic number, because the mean of its divisors is an integer number (174575100).

Almost surely, 2^1645993668 is an apocalyptic number.

It is an amenable number.

1645993668 is an abundant number, since it is smaller than the sum of its proper divisors (2543808732).

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

1645993668 is a wasteful number, since it uses less digits than its factorization.

1645993668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12469667 (or 12469665 counting only the distinct ones).

The product of its digits is 8398080, while the sum is 57.

The square root of 1645993668 is about 40570.8475139477. The cubic root of 1645993668 is about 1180.7085823636.

The spelling of 1645993668 in words is "one billion, six hundred forty-five million, nine hundred ninety-three thousand, six hundred sixty-eight".