21694453 has 12 divisors (see below), whose sum is σ = 24433164. Its totient is φ = 19236800.

The previous prime is 21694441. The next prime is 21694481. The reversal of 21694453 is 35449612.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 5750404 + 15944049 = 2398^2 + 3993^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21694453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21694423) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2775 + ... + 7147.

It is an arithmetic number, because the mean of its divisors is an integer number (2036097).

Almost surely, 2^21694453 is an apocalyptic number.

It is an amenable number.

21694453 is a deficient number, since it is larger than the sum of its proper divisors (2738711).

21694453 is a wasteful number, since it uses less digits than its factorization.

21694453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4436 (or 4425 counting only the distinct ones).

The product of its digits is 25920, while the sum is 34.

The square root of 21694453 is about 4657.7304559195. The cubic root of 21694453 is about 278.9006767808.

The spelling of 21694453 in words is "twenty-one million, six hundred ninety-four thousand, four hundred fifty-three".