21248313 has 16 divisors (see below), whose sum is σ = 29242176. Its totient is φ = 13717440.

The previous prime is 21248309. The next prime is 21248363. The reversal of 21248313 is 31384212.

It is not a de Polignac number, because 21248313 - 2² = 21248309 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21248303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11395 + ... + 13127.

It is an arithmetic number, because the mean of its divisors is an integer number (1827636).

Almost surely, 2^21248313 is an apocalyptic number.

It is an amenable number.

21248313 is a deficient number, since it is larger than the sum of its proper divisors (7993863).

21248313 is a wasteful number, since it uses less digits than its factorization.

21248313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1864.

The product of its digits is 1152, while the sum is 24.

The square root of 21248313 is about 4609.5892441735. The cubic root of 21248313 is about 276.9755829155.

The spelling of 21248313 in words is "twenty-one million, two hundred forty-eight thousand, three hundred thirteen".