1644664902 has 16 divisors (see below), whose sum is σ = 3294550272. Its totient is φ = 547351560.

The previous prime is 1644664891. The next prime is 1644664913. The reversal of 1644664902 is 2094664461.

It is an interprime number because it is at equal distance from previous prime (1644664891) and next prime (1644664913).

It is a congruent number.

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, 213418 + ... + 220989.

It is an arithmetic number, because the mean of its divisors is an integer number (205909392).

Almost surely, 2^1644664902 is an apocalyptic number.

1644664902 is an abundant number, since it is smaller than the sum of its proper divisors (1649885370).

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

1644664902 is a wasteful number, since it uses less digits than its factorization.

1644664902 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 435043.

The product of its (nonzero) digits is 248832, while the sum is 42.

The square root of 1644664902 is about 40554.4683358073. The cubic root of 1644664902 is about 1180.3907788360.

The spelling of 1644664902 in words is "one billion, six hundred forty-four million, six hundred sixty-four thousand, nine hundred two".