1644429312 has 228 divisors, whose sum is σ = 5152692636. Its totient is φ = 503316480.

The previous prime is 1644429257. The next prime is 1644429313. The reversal of 1644429312 is 2139244461.

1644429312 is a `hidden beast` number, since 1 + 644 + 4 + 2 + 9 + 3 + 1 + 2 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 603979776 + 1040449536 = 24576^2 + 32256^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (1644429313) 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, 40108012 + ... + 40108052.

Almost surely, 2^1644429312 is an apocalyptic number.

1644429312 is a gapful number since it is divisible by the number (12) 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 1644429312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2576346318).

1644429312 is an abundant number, since it is smaller than the sum of its proper divisors (3508263324).

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

1644429312 is an frugal number, since it uses more digits than its factorization.

1644429312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100 (or 63 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 1644429312 is about 40551.5636196682. The cubic root of 1644429312 is about 1180.3344144579.

The spelling of 1644429312 in words is "one billion, six hundred forty-four million, four hundred twenty-nine thousand, three hundred twelve".