21448723 has 2 divisors, whose sum is σ = 21448724. Its totient is φ = 21448722.

The previous prime is 21448711. The next prime is 21448793. The reversal of 21448723 is 32784412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21448723 - 2¹⁷ = 21317651 is a prime.

It is not a weakly prime, because it can be changed into another prime (21448793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10724361 + 10724362.

It is an arithmetic number, because the mean of its divisors is an integer number (10724362).

Almost surely, 2^21448723 is an apocalyptic number.

21448723 is a deficient number, since it is larger than the sum of its proper divisors (1).

21448723 is an equidigital number, since it uses as much as digits as its factorization.

21448723 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10752, while the sum is 31.

The square root of 21448723 is about 4631.2766058615. The cubic root of 21448723 is about 277.8436529216.

The spelling of 21448723 in words is "twenty-one million, four hundred forty-eight thousand, seven hundred twenty-three".