1644113121 has 24 divisors (see below), whose sum is σ = 2559128544. Its totient is φ = 936149760.

The previous prime is 1644113099. The next prime is 1644113131. The reversal of 1644113121 is 1213114461.

It is a happy number.

It is not a de Polignac number, because 1644113121 - 2¹⁴ = 1644096737 is a prime.

It is a super-3 number, since 3×1644113121³ (a number of 29 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1644113091 and 1644113100.

It is not an unprimeable number, because it can be changed into a prime (1644113131) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21841 + ... + 61361.

It is an arithmetic number, because the mean of its divisors is an integer number (106630356).

Almost surely, 2^1644113121 is an apocalyptic number.

It is an amenable number.

1644113121 is a deficient number, since it is larger than the sum of its proper divisors (915015423).

1644113121 is a wasteful number, since it uses less digits than its factorization.

1644113121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39821 (or 39814 counting only the distinct ones).

The product of its digits is 576, while the sum is 24.

The square root of 1644113121 is about 40547.6648032905. The cubic root of 1644113121 is about 1180.2587580100.

Adding to 1644113121 its reverse (1213114461), we get a palindrome (2857227582).

The spelling of 1644113121 in words is "one billion, six hundred forty-four million, one hundred thirteen thousand, one hundred twenty-one".