21432763872 has 216 divisors, whose sum is σ = 69883448544. Its totient is φ = 6206533632.

The previous prime is 21432763843. The next prime is 21432763879. The reversal of 21432763872 is 27836723412.

21432763872 is a `hidden beast` number, since 2 + 1 + 4 + 3 + 2 + 7 + 638 + 7 + 2 = 666.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21432763879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 814473 + ... + 840375.

It is an arithmetic number, because the mean of its divisors is an integer number (323534484).

Almost surely, 2^21432763872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21432763872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34941724272).

21432763872 is an abundant number, since it is smaller than the sum of its proper divisors (48450684672).

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

21432763872 is a wasteful number, since it uses less digits than its factorization.

21432763872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25962 (or 25938 counting only the distinct ones).

The product of its digits is 677376, while the sum is 45.

The spelling of 21432763872 in words is "twenty-one billion, four hundred thirty-two million, seven hundred sixty-three thousand, eight hundred seventy-two".