20660869 has 2 divisors, whose sum is σ = 20660870. Its totient is φ = 20660868.

The previous prime is 20660851. The next prime is 20660879. The reversal of 20660869 is 96806602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20657025 + 3844 = 4545^2 + 62^2 .

It is a cyclic number.

It is not a de Polignac number, because 20660869 - 2¹¹ = 20658821 is a prime.

It is a super-2 number, since 2×20660869² = 853743015670322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20660839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10330434 + 10330435.

It is an arithmetic number, because the mean of its divisors is an integer number (10330435).

Almost surely, 2^20660869 is an apocalyptic number.

It is an amenable number.

20660869 is a deficient number, since it is larger than the sum of its proper divisors (1).

20660869 is an equidigital number, since it uses as much as digits as its factorization.

20660869 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 37.

The square root of 20660869 is about 4545.4228626169. The cubic root of 20660869 is about 274.3992129461.

It can be divided in two parts, 206 and 60869, that added together give a triangular number (61075 = T₃₄₉).

The spelling of 20660869 in words is "twenty million, six hundred sixty thousand, eight hundred sixty-nine".