21332791 has 2 divisors, whose sum is σ = 21332792. Its totient is φ = 21332790.

The previous prime is 21332771. The next prime is 21332797. The reversal of 21332791 is 19723312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21332791 - 2²¹ = 19235639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21332797) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10666395 + 10666396.

It is an arithmetic number, because the mean of its divisors is an integer number (10666396).

Almost surely, 2^21332791 is an apocalyptic number.

21332791 is a deficient number, since it is larger than the sum of its proper divisors (1).

21332791 is an equidigital number, since it uses as much as digits as its factorization.

21332791 is an evil number, because the sum of its binary digits is even.

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

The square root of 21332791 is about 4618.7434438384. The cubic root of 21332791 is about 277.3421595145.

The spelling of 21332791 in words is "twenty-one million, three hundred thirty-two thousand, seven hundred ninety-one".