1644931116 has 72 divisors (see below), whose sum is σ = 4294914624. Its totient is φ = 530500320.

The previous prime is 1644931109. The next prime is 1644931139. The reversal of 1644931116 is 6111394461.

1644931116 is a `hidden beast` number, since 1 + 644 + 9 + 3 + 1 + 1 + 1 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 160671 + ... + 170601.

It is an arithmetic number, because the mean of its divisors is an integer number (59651592).

Almost surely, 2^1644931116 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1644931116, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2147457312).

1644931116 is an abundant number, since it is smaller than the sum of its proper divisors (2649983508).

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

1644931116 is a wasteful number, since it uses less digits than its factorization.

1644931116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10091 (or 10086 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 1644931116 is about 40557.7503814006. The cubic root of 1644931116 is about 1180.4544634600.

The spelling of 1644931116 in words is "one billion, six hundred forty-four million, nine hundred thirty-one thousand, one hundred sixteen".