21075297 has 8 divisors (see below), whose sum is σ = 28162944. Its totient is φ = 14018928.

The previous prime is 21075283. The next prime is 21075347. The reversal of 21075297 is 79257012.

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

It is not a de Polignac number, because 21075297 - 2⁷ = 21075169 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21075217) 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, 6198 + ... + 8975.

It is an arithmetic number, because the mean of its divisors is an integer number (3520368).

Almost surely, 2^21075297 is an apocalyptic number.

It is an amenable number.

21075297 is a deficient number, since it is larger than the sum of its proper divisors (7087647).

21075297 is a wasteful number, since it uses less digits than its factorization.

21075297 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15639.

The product of its (nonzero) digits is 8820, while the sum is 33.

The square root of 21075297 is about 4590.7839199858. The cubic root of 21075297 is about 276.2217683044.

The spelling of 21075297 in words is "twenty-one million, seventy-five thousand, two hundred ninety-seven".