21448013 has 4 divisors (see below), whose sum is σ = 21946848. Its totient is φ = 20949180.

The previous prime is 21448003. The next prime is 21448051. The reversal of 21448013 is 31084412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21448013 - 2¹⁰ = 21446989 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21448013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21448003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 249353 + ... + 249438.

It is an arithmetic number, because the mean of its divisors is an integer number (5486712).

Almost surely, 2^21448013 is an apocalyptic number.

It is an amenable number.

21448013 is a deficient number, since it is larger than the sum of its proper divisors (498835).

21448013 is an equidigital number, since it uses as much as digits as its factorization.

21448013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 498834.

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 21448013 is about 4631.1999524961. The cubic root of 21448013 is about 277.8405871421.

The spelling of 21448013 in words is "twenty-one million, four hundred forty-eight thousand, thirteen".