10644721920 has 432 divisors, whose sum is σ = 43658858880. Its totient is φ = 2432581632.

The previous prime is 10644721849. The next prime is 10644722063. The reversal of 10644721920 is 2912744601.

It is a happy number.

10644721920 is a `hidden beast` number, since 1 + 0 + 644 + 7 + 2 + 1 + 9 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

It is a super-2 number, since 2×10644721920² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2174836 + ... + 2179724.

Almost surely, 2^10644721920 is an apocalyptic number.

10644721920 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 10644721920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21829429440).

10644721920 is an abundant number, since it is smaller than the sum of its proper divisors (33014136960).

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

10644721920 is an frugal number, since it uses more digits than its factorization.

10644721920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4932 (or 4906 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The spelling of 10644721920 in words is "ten billion, six hundred forty-four million, seven hundred twenty-one thousand, nine hundred twenty".