1644149760 has 352 divisors, whose sum is σ = 5914225152. Its totient is φ = 386334720.

The previous prime is 1644149753. The next prime is 1644149761. The reversal of 1644149760 is 679414461.

It is a tau number, because it is divible by the number of its divisors (352).

It is a super-3 number, since 3×1644149760³ (a number of 29 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1644149761) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6251389 + ... + 6251651.

It is an arithmetic number, because the mean of its divisors is an integer number (16801776).

Almost surely, 2^1644149760 is an apocalyptic number.

1644149760 is a gapful number since it is divisible by the number (10) 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 1644149760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2957112576).

1644149760 is an abundant number, since it is smaller than the sum of its proper divisors (4270075392).

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

1644149760 is a wasteful number, since it uses less digits than its factorization.

1644149760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 339 (or 321 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 42.

The square root of 1644149760 is about 40548.1166023775. The cubic root of 1644149760 is about 1180.2675252858.

The spelling of 1644149760 in words is "one billion, six hundred forty-four million, one hundred forty-nine thousand, seven hundred sixty".