21044601600 has 216 divisors, whose sum is σ = 75766108992. Its totient is φ = 5101670400.

The previous prime is 21044601547. The next prime is 21044601601. The reversal of 21044601600 is 610644012.

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

It is not an unprimeable number, because it can be changed into a prime (21044601601) 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, 161379 + ... + 261021.

Almost surely, 2^21044601600 is an apocalyptic number.

21044601600 is a gapful number since it is divisible by the number (20) 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 21044601600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37883054496).

21044601600 is an abundant number, since it is smaller than the sum of its proper divisors (54721507392).

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

21044601600 is a wasteful number, since it uses less digits than its factorization.

21044601600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99683 (or 99664 counting only the distinct ones).

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

The spelling of 21044601600 in words is "twenty-one billion, forty-four million, six hundred one thousand, six hundred".