1644132256 has 48 divisors (see below), whose sum is σ = 3502584288. Its totient is φ = 755193600.

The previous prime is 1644132251. The next prime is 1644132257. The reversal of 1644132256 is 6522314461.

It is a super-3 number, since 3×1644132256³ (a number of 29 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1644132251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 78411 + ... + 97141.

It is an arithmetic number, because the mean of its divisors is an integer number (72970506).

Almost surely, 2^1644132256 is an apocalyptic number.

1644132256 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1644132256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1751292144).

1644132256 is an abundant number, since it is smaller than the sum of its proper divisors (1858452032).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1644132256 is a wasteful number, since it uses less digits than its factorization.

1644132256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18965 (or 18957 counting only the distinct ones).

The product of its digits is 34560, while the sum is 34.

The square root of 1644132256 is about 40547.9007594721. The cubic root of 1644132256 is about 1180.2633368036.

The spelling of 1644132256 in words is "one billion, six hundred forty-four million, one hundred thirty-two thousand, two hundred fifty-six".