21965029 has 2 divisors, whose sum is σ = 21965030. Its totient is φ = 21965028.

The previous prime is 21965017. The next prime is 21965033. The reversal of 21965029 is 92056912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21372129 + 592900 = 4623^2 + 770^2 .

It is a cyclic number.

It is not a de Polignac number, because 21965029 - 2¹⁷ = 21833957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21964985 and 21965003.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21965039) 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, 10982514 + 10982515.

It is an arithmetic number, because the mean of its divisors is an integer number (10982515).

Almost surely, 2^21965029 is an apocalyptic number.

It is an amenable number.

21965029 is a deficient number, since it is larger than the sum of its proper divisors (1).

21965029 is an equidigital number, since it uses as much as digits as its factorization.

21965029 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 21965029 is about 4686.6863560516. The cubic root of 21965029 is about 280.0553844523.

It can be divided in two parts, 2196 and 5029, that added together give a square (7225 = 85²).

The spelling of 21965029 in words is "twenty-one million, nine hundred sixty-five thousand, twenty-nine".