21133197 has 8 divisors (see below), whose sum is σ = 31308480. Its totient is φ = 14088780.

The previous prime is 21133153. The next prime is 21133213. The reversal of 21133197 is 79133112.

It is not a de Polignac number, because 21133197 - 2⁸ = 21132941 is a prime.

It is a super-2 number, since 2×21133197² = 893224030881618, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 782711 = 21133197 / (2 + 1 + 1 + 3 + 3 + 1 + 9 + 7).

It is a self number, because there is not a number n which added to its sum of digits gives 21133197.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21133897) 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 7 ways as a sum of consecutive naturals, for example, 391329 + ... + 391382.

It is an arithmetic number, because the mean of its divisors is an integer number (3913560).

Almost surely, 2^21133197 is an apocalyptic number.

21133197 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

21133197 is a deficient number, since it is larger than the sum of its proper divisors (10175283).

21133197 is an equidigital number, since it uses as much as digits as its factorization.

21133197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 782720 (or 782714 counting only the distinct ones).

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

The square root of 21133197 is about 4597.0857072715. The cubic root of 21133197 is about 276.4744909851.

The spelling of 21133197 in words is "twenty-one million, one hundred thirty-three thousand, one hundred ninety-seven".