21670453 has 8 divisors (see below), whose sum is σ = 25620480. Its totient is φ = 17934000.

The previous prime is 21670447. The next prime is 21670477. The reversal of 21670453 is 35407612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-21670453 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 (21670403) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53173 + ... + 53578.

It is an arithmetic number, because the mean of its divisors is an integer number (3202560).

Almost surely, 2^21670453 is an apocalyptic number.

It is an amenable number.

21670453 is a deficient number, since it is larger than the sum of its proper divisors (3950027).

21670453 is a wasteful number, since it uses less digits than its factorization.

21670453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106787.

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 21670453 is about 4655.1533809317. The cubic root of 21670453 is about 278.7977920160.

The spelling of 21670453 in words is "twenty-one million, six hundred seventy thousand, four hundred fifty-three".