21332771 has 2 divisors, whose sum is σ = 21332772. Its totient is φ = 21332770.

The previous prime is 21332761. The next prime is 21332791. The reversal of 21332771 is 17723312.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21332771 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21332771.

It is not a weakly prime, because it can be changed into another prime (21332711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10666385 + 10666386.

It is an arithmetic number, because the mean of its divisors is an integer number (10666386).

Almost surely, 2^21332771 is an apocalyptic number.

21332771 is a deficient number, since it is larger than the sum of its proper divisors (1).

21332771 is an equidigital number, since it uses as much as digits as its factorization.

21332771 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1764, while the sum is 26.

The square root of 21332771 is about 4618.7412787468. The cubic root of 21332771 is about 277.3420728429.

It can be divided in two parts, 21 and 332771, that multiplied together give a triangular number (6988191 = T₃₇₃₈).

The spelling of 21332771 in words is "twenty-one million, three hundred thirty-two thousand, seven hundred seventy-one".