21322191 has 16 divisors (see below), whose sum is σ = 31091328. Its totient is φ = 12890400.

The previous prime is 21322181. The next prime is 21322201. The reversal of 21322191 is 19122312.

It is an interprime number because it is at equal distance from previous prime (21322181) and next prime (21322201).

It is a de Polignac number, because none of the positive numbers 2^k-21322191 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21322181) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25561 + ... + 26381.

It is an arithmetic number, because the mean of its divisors is an integer number (1943208).

Almost surely, 2^21322191 is an apocalyptic number.

21322191 is a deficient number, since it is larger than the sum of its proper divisors (9769137).

21322191 is a wasteful number, since it uses less digits than its factorization.

21322191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1622.

The product of its digits is 216, while the sum is 21.

The square root of 21322191 is about 4617.5958030126. The cubic root of 21322191 is about 277.2962159411.

It can be divided in two parts, 213221 and 91, that added together give a palindrome (213312).

The spelling of 21322191 in words is "twenty-one million, three hundred twenty-two thousand, one hundred ninety-one".