21980252 has 48 divisors (see below), whose sum is σ = 47371968. Its totient is φ = 8709120.

The previous prime is 21980243. The next prime is 21980281. The reversal of 21980252 is 25208912.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28658 + ... + 29414.

It is an arithmetic number, because the mean of its divisors is an integer number (986916).

Almost surely, 2^21980252 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 21980252, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23685984).

21980252 is an abundant number, since it is smaller than the sum of its proper divisors (25391716).

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

21980252 is a wasteful number, since it uses less digits than its factorization.

21980252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 846 (or 844 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 21980252 is about 4688.3101433246. The cubic root of 21980252 is about 280.1200675538.

The spelling of 21980252 in words is "twenty-one million, nine hundred eighty thousand, two hundred fifty-two".