1644213120 has 256 divisors, whose sum is σ = 5771796480. Its totient is φ = 394813440.

The previous prime is 1644213113. The next prime is 1644213139. The reversal of 1644213120 is 213124461.

It is a super-3 number, since 3×1644213120³ (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 congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2681934 + ... + 2682546.

It is an arithmetic number, because the mean of its divisors is an integer number (22546080).

Almost surely, 2^1644213120 is an apocalyptic number.

1644213120 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 1644213120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2885898240).

1644213120 is an abundant number, since it is smaller than the sum of its proper divisors (4127583360).

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

1644213120 is a wasteful number, since it uses less digits than its factorization.

1644213120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 773 (or 761 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 1644213120 is about 40548.8978888453. The cubic root of 1644213120 is about 1180.2826862709.

Adding to 1644213120 its reverse (213124461), we get a palindrome (1857337581).

The spelling of 1644213120 in words is "one billion, six hundred forty-four million, two hundred thirteen thousand, one hundred twenty".