1644172272 has 120 divisors (see below), whose sum is σ = 4918386096. Its totient is φ = 510916608.

The previous prime is 1644172267. The next prime is 1644172291. The reversal of 1644172272 is 2722714461.

1644172272 is a `hidden beast` number, since 1 + 644 + 1 + 7 + 2 + 2 + 7 + 2 = 666.

It is a super-3 number, since 3×1644172272³ (a number of 29 digits) contains 333 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 258798 + ... + 265074.

Almost surely, 2^1644172272 is an apocalyptic number.

1644172272 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 1644172272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2459193048).

1644172272 is an abundant number, since it is smaller than the sum of its proper divisors (3274213824).

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

1644172272 is a wasteful number, since it uses less digits than its factorization.

1644172272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6415 (or 6406 counting only the distinct ones).

The product of its digits is 37632, while the sum is 36.

The square root of 1644172272 is about 40548.3941975512. The cubic root of 1644172272 is about 1180.2729120743.

The spelling of 1644172272 in words is "one billion, six hundred forty-four million, one hundred seventy-two thousand, two hundred seventy-two".