1644023040 has 144 divisors (see below), whose sum is σ = 5728072896. Its totient is φ = 398540800.

The previous prime is 1644023033. The next prime is 1644023057. The reversal of 1644023040 is 403204461.

It is a super-3 number, since 3×1644023040³ (a number of 29 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 1644023040.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22780 + ... + 61700.

It is an arithmetic number, because the mean of its divisors is an integer number (39778284).

Almost surely, 2^1644023040 is an apocalyptic number.

1644023040 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 1644023040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2864036448).

1644023040 is an abundant number, since it is smaller than the sum of its proper divisors (4084049856).

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

1644023040 is a wasteful number, since it uses less digits than its factorization.

1644023040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38956 (or 38942 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 1644023040 is about 40546.5539842784. The cubic root of 1644023040 is about 1180.2372021471.

It can be divided in two parts, 164 and 4023040, that added together give a palindrome (4023204).

The spelling of 1644023040 in words is "one billion, six hundred forty-four million, twenty-three thousand, forty".