21769837 has 2 divisors, whose sum is σ = 21769838. Its totient is φ = 21769836.

The previous prime is 21769831. The next prime is 21769849. The reversal of 21769837 is 73896712.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14699556 + 7070281 = 3834^2 + 2659^2 .

It is a cyclic number.

It is not a de Polignac number, because 21769837 - 2³ = 21769829 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21769793 and 21769802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21769831) 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, 10884918 + 10884919.

It is an arithmetic number, because the mean of its divisors is an integer number (10884919).

Almost surely, 2^21769837 is an apocalyptic number.

It is an amenable number.

21769837 is a deficient number, since it is larger than the sum of its proper divisors (1).

21769837 is an equidigital number, since it uses as much as digits as its factorization.

21769837 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 127008, while the sum is 43.

The square root of 21769837 is about 4665.8157914774. The cubic root of 21769837 is about 279.2233451811.

The spelling of 21769837 in words is "twenty-one million, seven hundred sixty-nine thousand, eight hundred thirty-seven".