21122529552 has 120 divisors (see below), whose sum is σ = 61288755840. Its totient is φ = 6782872320.

The previous prime is 21122529509. The next prime is 21122529553. The reversal of 21122529552 is 25592522112.

21122529552 is a `hidden beast` number, since 2 + 1 + 122 + 529 + 5 + 5 + 2 = 666.

It is a super-3 number, since 3×21122529552³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

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

It is not an unprimeable number, because it can be changed into a prime (21122529553) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1944777 + ... + 1955607.

It is an arithmetic number, because the mean of its divisors is an integer number (510739632).

Almost surely, 2^21122529552 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 21122529552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30644377920).

21122529552 is an abundant number, since it is smaller than the sum of its proper divisors (40166226288).

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

21122529552 is a wasteful number, since it uses less digits than its factorization.

21122529552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11341 (or 11332 counting only the distinct ones).

The product of its digits is 36000, while the sum is 36.

The spelling of 21122529552 in words is "twenty-one billion, one hundred twenty-two million, five hundred twenty-nine thousand, five hundred fifty-two".