1644268395 has 48 divisors (see below), whose sum is σ = 3304869120. Its totient is φ = 683327040.

The previous prime is 1644268393. The next prime is 1644268421. The reversal of 1644268395 is 5938624461.

1644268395 = 4583² + 4584² + ... + 4659².

It is not a de Polignac number, because 1644268395 - 2¹ = 1644268393 is a prime.

It is a super-3 number, since 3×1644268395³ (a number of 29 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1644268393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 52005 + ... + 77414.

It is an arithmetic number, because the mean of its divisors is an integer number (68851440).

Almost surely, 2^1644268395 is an apocalyptic number.

1644268395 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1644268395 is an abundant number, since it is smaller than the sum of its proper divisors (1660600725).

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

1644268395 is a wasteful number, since it uses less digits than its factorization.

1644268395 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129456 (or 129445 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 48.

The square root of 1644268395 is about 40549.5794676098. The cubic root of 1644268395 is about 1180.2959123329.

The spelling of 1644268395 in words is "one billion, six hundred forty-four million, two hundred sixty-eight thousand, three hundred ninety-five".