1644978212 has 12 divisors (see below), whose sum is σ = 2879134860. Its totient is φ = 822368256.

The previous prime is 1644978199. The next prime is 1644978221. The reversal of 1644978212 is 2128794461.

It can be written as a sum of positive squares in 2 ways, for example, as 682985956 + 961992256 = 26134^2 + 31016^2 .

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, 4964 + ... + 57572.

It is an arithmetic number, because the mean of its divisors is an integer number (239927905).

Almost surely, 2^1644978212 is an apocalyptic number.

It is an amenable number.

1644978212 is a deficient number, since it is larger than the sum of its proper divisors (1234156648).

1644978212 is a wasteful number, since it uses less digits than its factorization.

1644978212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60430 (or 60428 counting only the distinct ones).

The product of its digits is 193536, while the sum is 44.

The square root of 1644978212 is about 40558.3309814396. The cubic root of 1644978212 is about 1180.4657292109.

The spelling of 1644978212 in words is "one billion, six hundred forty-four million, nine hundred seventy-eight thousand, two hundred twelve".