1644242566 has 8 divisors (see below), whose sum is σ = 2501101584. Its totient is φ = 810542040.

The previous prime is 1644242543. The next prime is 1644242581. The reversal of 1644242566 is 6652424461.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-3 number, since 3×1644242566³ (a number of 29 digits) contains 333 as substring.

It is a congruent number.

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, 5789445 + ... + 5789728.

It is an arithmetic number, because the mean of its divisors is an integer number (312637698).

Almost surely, 2^1644242566 is an apocalyptic number.

1644242566 is a deficient number, since it is larger than the sum of its proper divisors (856859018).

1644242566 is a wasteful number, since it uses less digits than its factorization.

1644242566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11579246.

The product of its digits is 276480, while the sum is 40.

The square root of 1644242566 is about 40549.2609797022. The cubic root of 1644242566 is about 1180.2897320721.

The spelling of 1644242566 in words is "one billion, six hundred forty-four million, two hundred forty-two thousand, five hundred sixty-six".