1644071121 has 64 divisors (see below), whose sum is σ = 3196569600. Its totient is φ = 809092800.

The previous prime is 1644071113. The next prime is 1644071137. The reversal of 1644071121 is 1211704461.

1644071121 is a `hidden beast` number, since 1 + 644 + 0 + 7 + 1 + 12 + 1 = 666.

1644071121 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1644071121 - 2³ = 1644071113 is a prime.

It is a super-3 number, since 3×1644071121³ (a number of 29 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1644071111) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 18691 + ... + 60311.

It is an arithmetic number, because the mean of its divisors is an integer number (49946400).

Almost surely, 2^1644071121 is an apocalyptic number.

1644071121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1644071121 is a deficient number, since it is larger than the sum of its proper divisors (1552498479).

1644071121 is a wasteful number, since it uses less digits than its factorization.

1644071121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41667 (or 41661 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 1644071121 is about 40547.1468909959. The cubic root of 1644071121 is about 1180.2487077506.

Adding to 1644071121 its reverse (1211704461), we get a palindrome (2855775582).

The spelling of 1644071121 in words is "one billion, six hundred forty-four million, seventy-one thousand, one hundred twenty-one".