1644474220 has 24 divisors (see below), whose sum is σ = 3465194544. Its totient is φ = 655542336.

The previous prime is 1644474193. The next prime is 1644474259. The reversal of 1644474220 is 224744461.

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, 134454 + ... + 146173.

It is an arithmetic number, because the mean of its divisors is an integer number (144383106).

Almost surely, 2^1644474220 is an apocalyptic number.

1644474220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1644474220 is an abundant number, since it is smaller than the sum of its proper divisors (1820720324).

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

1644474220 is a wasteful number, since it uses less digits than its factorization.

1644474220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280929 (or 280927 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 34.

The square root of 1644474220 is about 40552.1173306647. The cubic root of 1644474220 is about 1180.3451590113.

The spelling of 1644474220 in words is "one billion, six hundred forty-four million, four hundred seventy-four thousand, two hundred twenty".