21297895 has 4 divisors (see below), whose sum is σ = 25557480. Its totient is φ = 17038312.

The previous prime is 21297869. The next prime is 21297907. The reversal of 21297895 is 59879212.

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

It is a cyclic number.

It is not a de Polignac number, because 21297895 - 2⁵ = 21297863 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2129785 + ... + 2129794.

It is an arithmetic number, because the mean of its divisors is an integer number (6389370).

Almost surely, 2^21297895 is an apocalyptic number.

21297895 is a deficient number, since it is larger than the sum of its proper divisors (4259585).

21297895 is an equidigital number, since it uses as much as digits as its factorization.

21297895 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4259584.

The product of its digits is 90720, while the sum is 43.

The square root of 21297895 is about 4614.9642468821. The cubic root of 21297895 is about 277.1908523253.

The spelling of 21297895 in words is "twenty-one million, two hundred ninety-seven thousand, eight hundred ninety-five".