21299976 has 64 divisors (see below), whose sum is σ = 61094400. Its totient is φ = 6868800.

The previous prime is 21299959. The next prime is 21299983. The reversal of 21299976 is 67999212.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5106 + ... + 8286.

It is an arithmetic number, because the mean of its divisors is an integer number (954600).

Almost surely, 2^21299976 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 21299976, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30547200).

21299976 is an abundant number, since it is smaller than the sum of its proper divisors (39794424).

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

21299976 is a wasteful number, since it uses less digits than its factorization.

21299976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3227 (or 3217 counting only the distinct ones).

The product of its digits is 122472, while the sum is 45.

The square root of 21299976 is about 4615.1897035767. The cubic root of 21299976 is about 277.1998800622.

It can be divided in two parts, 2 and 1299976, that multiplied together give a palindrome (2599952).

The spelling of 21299976 in words is "twenty-one million, two hundred ninety-nine thousand, nine hundred seventy-six".