21366454 has 4 divisors (see below), whose sum is σ = 32049684. Its totient is φ = 10683226.

The previous prime is 21366407. The next prime is 21366463. The reversal of 21366454 is 45466312.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5341612 + ... + 5341615.

It is an arithmetic number, because the mean of its divisors is an integer number (8012421).

Almost surely, 2^21366454 is an apocalyptic number.

21366454 is a deficient number, since it is larger than the sum of its proper divisors (10683230).

21366454 is a wasteful number, since it uses less digits than its factorization.

21366454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10683229.

The product of its digits is 17280, while the sum is 31.

The square root of 21366454 is about 4622.3861803186. The cubic root of 21366454 is about 277.4879641995.

The spelling of 21366454 in words is "twenty-one million, three hundred sixty-six thousand, four hundred fifty-four".