21066454 has 4 divisors (see below), whose sum is σ = 31599684. Its totient is φ = 10533226.

The previous prime is 21066449. The next prime is 21066457. The reversal of 21066454 is 45466012.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21066457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5266612 + ... + 5266615.

It is an arithmetic number, because the mean of its divisors is an integer number (7899921).

Almost surely, 2^21066454 is an apocalyptic number.

21066454 is a deficient number, since it is larger than the sum of its proper divisors (10533230).

21066454 is a wasteful number, since it uses less digits than its factorization.

21066454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10533229.

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 21066454 is about 4589.8206936655. The cubic root of 21066454 is about 276.1831295320.

The spelling of 21066454 in words is "twenty-one million, sixty-six thousand, four hundred fifty-four".