21248799 has 16 divisors (see below), whose sum is σ = 33285504. Its totient is φ = 11887200.

The previous prime is 21248779. The next prime is 21248807. The reversal of 21248799 is 99784212.

It is not a de Polignac number, because 21248799 - 2⁸ = 21248543 is a prime.

It is a super-2 number, since 2×21248799² = 903022917884802, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21248799.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21248719) by changing a digit.

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, 24337 + ... + 25194.

It is an arithmetic number, because the mean of its divisors is an integer number (2080344).

Almost surely, 2^21248799 is an apocalyptic number.

21248799 is a deficient number, since it is larger than the sum of its proper divisors (12036705).

21248799 is a wasteful number, since it uses less digits than its factorization.

21248799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49558.

The product of its digits is 72576, while the sum is 42.

The square root of 21248799 is about 4609.6419600659. The cubic root of 21248799 is about 276.9776945986.

The spelling of 21248799 in words is "twenty-one million, two hundred forty-eight thousand, seven hundred ninety-nine".