1644227916 has 24 divisors (see below), whose sum is σ = 3899427504. Its totient is φ = 539090880.

The previous prime is 1644227899. The next prime is 1644227917. The reversal of 1644227916 is 6197224461.

It is a super-3 number, since 3×1644227916³ (a number of 29 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1644227917) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1122375 + ... + 1123838.

It is an arithmetic number, because the mean of its divisors is an integer number (162476146).

Almost surely, 2^1644227916 is an apocalyptic number.

It is an amenable number.

1644227916 is an abundant number, since it is smaller than the sum of its proper divisors (2255199588).

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

1644227916 is a wasteful number, since it uses less digits than its factorization.

1644227916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2246281 (or 2246279 counting only the distinct ones).

The product of its digits is 145152, while the sum is 42.

The square root of 1644227916 is about 40549.0803348239. The cubic root of 1644227916 is about 1180.2862266493.

The spelling of 1644227916 in words is "one billion, six hundred forty-four million, two hundred twenty-seven thousand, nine hundred sixteen".