21197115 has 48 divisors (see below), whose sum is σ = 39124800. Its totient is φ = 10596096.

The previous prime is 21197093. The next prime is 21197117. The reversal of 21197115 is 51179112.

It is not a de Polignac number, because 21197115 - 2²⁰ = 20148539 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21197117) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 48066 + ... + 48504.

It is an arithmetic number, because the mean of its divisors is an integer number (815100).

Almost surely, 2^21197115 is an apocalyptic number.

21197115 is a deficient number, since it is larger than the sum of its proper divisors (17927685).

21197115 is a wasteful number, since it uses less digits than its factorization.

21197115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 516 (or 513 counting only the distinct ones).

The product of its digits is 630, while the sum is 27.

The square root of 21197115 is about 4604.0324716492. The cubic root of 21197115 is about 276.7529456237.

It can be divided in two parts, 21197 and 115, that added together give a palindrome (21312).

The spelling of 21197115 in words is "twenty-one million, one hundred ninety-seven thousand, one hundred fifteen".