21769361 has 2 divisors, whose sum is σ = 21769362. Its totient is φ = 21769360.

The previous prime is 21769327. The next prime is 21769393. The reversal of 21769361 is 16396712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20079361 + 1690000 = 4481^2 + 1300^2 .

It is a cyclic number.

It is not a de Polignac number, because 21769361 - 2¹⁰ = 21768337 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21769301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10884680 + 10884681.

It is an arithmetic number, because the mean of its divisors is an integer number (10884681).

Almost surely, 2^21769361 is an apocalyptic number.

It is an amenable number.

21769361 is a deficient number, since it is larger than the sum of its proper divisors (1).

21769361 is an equidigital number, since it uses as much as digits as its factorization.

21769361 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13608, while the sum is 35.

The square root of 21769361 is about 4665.7647818980. The cubic root of 21769361 is about 279.2213100827.

The spelling of 21769361 in words is "twenty-one million, seven hundred sixty-nine thousand, three hundred sixty-one".