21769907 has 2 divisors, whose sum is σ = 21769908. Its totient is φ = 21769906.

The previous prime is 21769903. The next prime is 21769931. The reversal of 21769907 is 70996712.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21769907 - 2² = 21769903 is a prime.

It is not a weakly prime, because it can be changed into another prime (21769903) 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, 10884953 + 10884954.

It is an arithmetic number, because the mean of its divisors is an integer number (10884954).

Almost surely, 2^21769907 is an apocalyptic number.

21769907 is a deficient number, since it is larger than the sum of its proper divisors (1).

21769907 is an equidigital number, since it uses as much as digits as its factorization.

21769907 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 47628, while the sum is 41.

The square root of 21769907 is about 4665.8232928391. The cubic root of 21769907 is about 279.2236444578.

The spelling of 21769907 in words is "twenty-one million, seven hundred sixty-nine thousand, nine hundred seven".