21752496 has 80 divisors (see below), whose sum is σ = 63944320. Its totient is φ = 7076160.

The previous prime is 21752461. The next prime is 21752519. The reversal of 21752496 is 69425712.

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

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 21752496.

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, 17991 + ... + 19161.

It is an arithmetic number, because the mean of its divisors is an integer number (799304).

Almost surely, 2^21752496 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 21752496, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31972160).

21752496 is an abundant number, since it is smaller than the sum of its proper divisors (42191824).

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

21752496 is a wasteful number, since it uses less digits than its factorization.

21752496 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1231 (or 1219 counting only the distinct ones).

The product of its digits is 30240, while the sum is 36.

The square root of 21752496 is about 4663.9571181562. The cubic root of 21752496 is about 279.1491860246.

The spelling of 21752496 in words is "twenty-one million, seven hundred fifty-two thousand, four hundred ninety-six".