21497073 has 8 divisors (see below), whose sum is σ = 30867648. Its totient is φ = 13228944.

The previous prime is 21497057. The next prime is 21497087. The reversal of 21497073 is 37079412.

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

It is not a de Polignac number, because 21497073 - 2⁴ = 21497057 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21497023) 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, 275565 + ... + 275642.

It is an arithmetic number, because the mean of its divisors is an integer number (3858456).

Almost surely, 2^21497073 is an apocalyptic number.

It is an amenable number.

21497073 is a deficient number, since it is larger than the sum of its proper divisors (9370575).

21497073 is a wasteful number, since it uses less digits than its factorization.

21497073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 551223.

The product of its (nonzero) digits is 10584, while the sum is 33.

The square root of 21497073 is about 4636.4936104776. The cubic root of 21497073 is about 278.0522692119.

The spelling of 21497073 in words is "twenty-one million, four hundred ninety-seven thousand, seventy-three".