1644868355 has 32 divisors (see below), whose sum is σ = 2168694528. Its totient is φ = 1190246400.

The previous prime is 1644868349. The next prime is 1644868369. The reversal of 1644868355 is 5538684461.

It is not a de Polignac number, because 1644868355 - 2¹⁰ = 1644867331 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1335590 + ... + 1336820.

It is an arithmetic number, because the mean of its divisors is an integer number (67771704).

Almost surely, 2^1644868355 is an apocalyptic number.

1644868355 is a deficient number, since it is larger than the sum of its proper divisors (523826173).

1644868355 is a wasteful number, since it uses less digits than its factorization.

1644868355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1647.

The product of its digits is 2764800, while the sum is 50.

The square root of 1644868355 is about 40556.9766501400. The cubic root of 1644868355 is about 1180.4394501778.

The spelling of 1644868355 in words is "one billion, six hundred forty-four million, eight hundred sixty-eight thousand, three hundred fifty-five".