21650547672 has 128 divisors (see below), whose sum is σ = 65566872000. Its totient is φ = 6661636992.

The previous prime is 21650547599. The next prime is 21650547673. The reversal of 21650547672 is 27674505612.

21650547672 is a `hidden beast` number, since 2 + 1 + 6 + 505 + 4 + 76 + 72 = 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 (21650547673) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 179854 + ... + 275042.

Almost surely, 2^21650547672 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 21650547672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32783436000).

21650547672 is an abundant number, since it is smaller than the sum of its proper divisors (43916324328).

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

21650547672 is an equidigital number, since it uses as much as digits as its factorization.

21650547672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95229 (or 95207 counting only the distinct ones).

The product of its (nonzero) digits is 705600, while the sum is 45.

The spelling of 21650547672 in words is "twenty-one billion, six hundred fifty million, five hundred forty-seven thousand, six hundred seventy-two".