1644252266 has 16 divisors (see below), whose sum is σ = 2552407200. Its totient is φ = 793471728.

The previous prime is 1644252263. The next prime is 1644252271. The reversal of 1644252266 is 6622524461.

It is a super-4 number, since 4×1644252266⁴ (a number of 38 digits) contains 4444 as substring. Note that it is a super-d number also for d = 3, 2.

It is not an unprimeable number, because it can be changed into a prime (1644252263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 245105 + ... + 251723.

It is an arithmetic number, because the mean of its divisors is an integer number (159525450).

Almost surely, 2^1644252266 is an apocalyptic number.

1644252266 is a deficient number, since it is larger than the sum of its proper divisors (908154934).

1644252266 is a wasteful number, since it uses less digits than its factorization.

1644252266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10933.

The product of its digits is 138240, while the sum is 38.

The square root of 1644252266 is about 40549.3805871310. The cubic root of 1644252266 is about 1180.2920530573.

The spelling of 1644252266 in words is "one billion, six hundred forty-four million, two hundred fifty-two thousand, two hundred sixty-six".