21117295 has 4 divisors (see below), whose sum is σ = 25340760. Its totient is φ = 16893832.

The previous prime is 21117277. The next prime is 21117311. The reversal of 21117295 is 59271112.

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 21117295 - 2⁵ = 21117263 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2111725 + ... + 2111734.

It is an arithmetic number, because the mean of its divisors is an integer number (6335190).

Almost surely, 2^21117295 is an apocalyptic number.

21117295 is a deficient number, since it is larger than the sum of its proper divisors (4223465).

21117295 is an equidigital number, since it uses as much as digits as its factorization.

21117295 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4223464.

The product of its digits is 1260, while the sum is 28.

The square root of 21117295 is about 4595.3558077694. The cubic root of 21117295 is about 276.4051277529.

It can be divided in two parts, 21117 and 295, that added together give a palindrome (21412).

The spelling of 21117295 in words is "twenty-one million, one hundred seventeen thousand, two hundred ninety-five".