21337191 has 12 divisors (see below), whose sum is σ = 31109832. Its totient is φ = 14091216.

The previous prime is 21337181. The next prime is 21337213. The reversal of 21337191 is 19173312.

It is not a de Polignac number, because 21337191 - 2¹¹ = 21335143 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21337181) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10116 + ... + 12041.

It is an arithmetic number, because the mean of its divisors is an integer number (2592486).

Almost surely, 2^21337191 is an apocalyptic number.

21337191 is a deficient number, since it is larger than the sum of its proper divisors (9772641).

21337191 is a wasteful number, since it uses less digits than its factorization.

21337191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22270 (or 22267 counting only the distinct ones).

The product of its digits is 1134, while the sum is 27.

The square root of 21337191 is about 4619.2197393066. The cubic root of 21337191 is about 277.3612259619.

It can be divided in two parts, 21337 and 191, that added together give a triangular number (21528 = T₂₀₇).

The spelling of 21337191 in words is "twenty-one million, three hundred thirty-seven thousand, one hundred ninety-one".