21323197 has 8 divisors (see below), whose sum is σ = 24401600. Its totient is φ = 18252864.

The previous prime is 21323191. The next prime is 21323209. The reversal of 21323197 is 79132312.

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

It is not a de Polignac number, because 21323197 - 2³ = 21323189 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21323191) 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, 5554 + ... + 8572.

It is an arithmetic number, because the mean of its divisors is an integer number (3050200).

Almost surely, 2^21323197 is an apocalyptic number.

It is an amenable number.

21323197 is a deficient number, since it is larger than the sum of its proper divisors (3078403).

21323197 is a wasteful number, since it uses less digits than its factorization.

21323197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4035.

The product of its digits is 2268, while the sum is 28.

The square root of 21323197 is about 4617.7047328732. The cubic root of 21323197 is about 277.3005769002.

It can be divided in two parts, 2132 and 3197, that added together give a square (5329 = 73²).

The spelling of 21323197 in words is "twenty-one million, three hundred twenty-three thousand, one hundred ninety-seven".