21769849 has 2 divisors, whose sum is σ = 21769850. Its totient is φ = 21769848.

The previous prime is 21769837. The next prime is 21769861. The reversal of 21769849 is 94896712.

It is a balanced prime because it is at equal distance from previous prime (21769837) and next prime (21769861).

It can be written as a sum of positive squares in only one way, i.e., 16548624 + 5221225 = 4068^2 + 2285^2 .

It is a cyclic number.

It is not a de Polignac number, because 21769849 - 2⁵ = 21769817 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21769799 and 21769808.

It is not a weakly prime, because it can be changed into another prime (21769829) 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 as a sum of consecutive naturals, namely, 10884924 + 10884925.

It is an arithmetic number, because the mean of its divisors is an integer number (10884925).

Almost surely, 2^21769849 is an apocalyptic number.

It is an amenable number.

21769849 is a deficient number, since it is larger than the sum of its proper divisors (1).

21769849 is an equidigital number, since it uses as much as digits as its factorization.

21769849 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 217728, while the sum is 46.

The square root of 21769849 is about 4665.8170774260. The cubic root of 21769849 is about 279.2233964857.

The spelling of 21769849 in words is "twenty-one million, seven hundred sixty-nine thousand, eight hundred forty-nine".