21667076172 has 108 divisors (see below), whose sum is σ = 63809685576. Its totient is φ = 6181056000.

The previous prime is 21667076149. The next prime is 21667076191. The reversal of 21667076172 is 27167076612.

21667076172 is a `hidden beast` number, since 21 + 6 + 6 + 7 + 0 + 7 + 617 + 2 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1178047 + ... + 1196297.

It is an arithmetic number, because the mean of its divisors is an integer number (590830422).

Almost surely, 2^21667076172 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 21667076172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31904842788).

21667076172 is an abundant number, since it is smaller than the sum of its proper divisors (42142609404).

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

21667076172 is a wasteful number, since it uses less digits than its factorization.

21667076172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18948 (or 18936 counting only the distinct ones).

The product of its (nonzero) digits is 296352, while the sum is 45.

The spelling of 21667076172 in words is "twenty-one billion, six hundred sixty-seven million, seventy-six thousand, one hundred seventy-two".