21771107249 has 2 divisors, whose sum is σ = 21771107250. Its totient is φ = 21771107248.

The previous prime is 21771107227. The next prime is 21771107333. The reversal of 21771107249 is 94270117712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16946832400 + 4824274849 = 130180^2 + 69457^2 .

It is a cyclic number.

It is not a de Polignac number, because 21771107249 - 2⁸ = 21771106993 is a prime.

It is a super-2 number, since 2×21771107249² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21771107849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10885553624 + 10885553625.

It is an arithmetic number, because the mean of its divisors is an integer number (10885553625).

Almost surely, 2^21771107249 is an apocalyptic number.

It is an amenable number.

21771107249 is a deficient number, since it is larger than the sum of its proper divisors (1).

21771107249 is an equidigital number, since it uses as much as digits as its factorization.

21771107249 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 49392, while the sum is 41.

The spelling of 21771107249 in words is "twenty-one billion, seven hundred seventy-one million, one hundred seven thousand, two hundred forty-nine".