21524822172 has 48 divisors (see below), whose sum is σ = 63777253120. Its totient is φ = 6149948976.

The previous prime is 21524822171. The next prime is 21524822173. The reversal of 21524822172 is 27122842512.

It is a happy number.

21524822172 is a `hidden beast` number, since 2 + 1 + 5 + 2 + 482 + 2 + 172 = 666.

It is an interprime number because it is at equal distance from previous prime (21524822171) and next prime (21524822173).

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 (21524822171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14235238 + ... + 14236749.

Almost surely, 2^21524822172 is an apocalyptic number.

It is an amenable number.

21524822172 is an abundant number, since it is smaller than the sum of its proper divisors (42252430948).

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

21524822172 is a wasteful number, since it uses less digits than its factorization.

21524822172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28472007 (or 28471999 counting only the distinct ones).

The product of its digits is 35840, while the sum is 36.

The spelling of 21524822172 in words is "twenty-one billion, five hundred twenty-four million, eight hundred twenty-two thousand, one hundred seventy-two".