1644335361 has 12 divisors (see below), whose sum is σ = 2389724688. Its totient is φ = 1089497304.

The previous prime is 1644335359. The next prime is 1644335383. The reversal of 1644335361 is 1635334461.

1644335361 is a `hidden beast` number, since 1 + 644 + 3 + 3 + 5 + 3 + 6 + 1 = 666.

It is not a de Polignac number, because 1644335361 - 2¹ = 1644335359 is a prime.

It is a super-3 number, since 3×1644335361³ (a number of 29 digits) contains 333 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (1644335321) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 558975 + ... + 561908.

It is an arithmetic number, because the mean of its divisors is an integer number (199143724).

Almost surely, 2^1644335361 is an apocalyptic number.

It is an amenable number.

1644335361 is a deficient number, since it is larger than the sum of its proper divisors (745389327).

1644335361 is a wasteful number, since it uses less digits than its factorization.

1644335361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1121052 (or 1121049 counting only the distinct ones).

The product of its digits is 77760, while the sum is 36.

The square root of 1644335361 is about 40550.4051890977. The cubic root of 1644335361 is about 1180.3119353908.

The spelling of 1644335361 in words is "one billion, six hundred forty-four million, three hundred thirty-five thousand, three hundred sixty-one".