1918765644 has 12 divisors (see below), whose sum is σ = 4477119864. Its totient is φ = 639588544.

The previous prime is 1918765621. The next prime is 1918765669. The reversal of 1918765644 is 4465678191.

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

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, 79948557 + ... + 79948580.

It is an arithmetic number, because the mean of its divisors is an integer number (373093322).

Almost surely, 2^1918765644 is an apocalyptic number.

It is an amenable number.

1918765644 is an abundant number, since it is smaller than the sum of its proper divisors (2558354220).

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

1918765644 is a wasteful number, since it uses less digits than its factorization.

1918765644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159897144 (or 159897142 counting only the distinct ones).

The product of its digits is 1451520, while the sum is 51.

The square root of 1918765644 is about 43803.7172395220. The cubic root of 1918765644 is about 1242.6265959020.

The spelling of 1918765644 in words is "one billion, nine hundred eighteen million, seven hundred sixty-five thousand, six hundred forty-four".