21066673 has 8 divisors (see below), whose sum is σ = 21844800. Its totient is φ = 20292048.

The previous prime is 21066641. The next prime is 21066677. The reversal of 21066673 is 37666012.

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

It is a cyclic number.

It is not a de Polignac number, because 21066673 - 2⁵ = 21066641 is a prime.

It is a super-2 number, since 2×21066673² = 887609422577858, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21066677) 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, 20940 + ... + 21922.

It is an arithmetic number, because the mean of its divisors is an integer number (2730600).

Almost surely, 2^21066673 is an apocalyptic number.

It is an amenable number.

21066673 is a deficient number, since it is larger than the sum of its proper divisors (778127).

21066673 is an equidigital number, since it uses as much as digits as its factorization.

21066673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1751.

The product of its (nonzero) digits is 9072, while the sum is 31.

The square root of 21066673 is about 4589.8445507446. The cubic root of 21066673 is about 276.1840865654.

The spelling of 21066673 in words is "twenty-one million, sixty-six thousand, six hundred seventy-three".