21144195072 has 832 divisors, whose sum is σ = 84546846720. Its totient is φ = 5042995200.

The previous prime is 21144195031. The next prime is 21144195073. The reversal of 21144195072 is 27059144112.

21144195072 is a `hidden beast` number, since 2 + 1 + 144 + 1 + 9 + 507 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (832).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21144195073) 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, 110702497 + ... + 110702687.

Almost surely, 2^21144195072 is an apocalyptic number.

21144195072 is a gapful number since it is divisible by the number (22) 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 21144195072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42273423360).

21144195072 is an abundant number, since it is smaller than the sum of its proper divisors (63402651648).

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

21144195072 is a wasteful number, since it uses less digits than its factorization.

21144195072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255 (or 227 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The spelling of 21144195072 in words is "twenty-one billion, one hundred forty-four million, one hundred ninety-five thousand, seventy-two".