21495673 has 2 divisors, whose sum is σ = 21495674. Its totient is φ = 21495672.

The previous prime is 21495671. The next prime is 21495703. The reversal of 21495673 is 37659412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13155129 + 8340544 = 3627^2 + 2888^2 .

It is a cyclic number.

It is not a de Polignac number, because 21495673 - 2¹ = 21495671 is a prime.

Together with 21495671, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21495671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10747836 + 10747837.

It is an arithmetic number, because the mean of its divisors is an integer number (10747837).

Almost surely, 2^21495673 is an apocalyptic number.

It is an amenable number.

21495673 is a deficient number, since it is larger than the sum of its proper divisors (1).

21495673 is an equidigital number, since it uses as much as digits as its factorization.

21495673 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45360, while the sum is 37.

The square root of 21495673 is about 4636.3426318597. The cubic root of 21495673 is about 278.0462330160.

The spelling of 21495673 in words is "twenty-one million, four hundred ninety-five thousand, six hundred seventy-three".