20660669 has 2 divisors, whose sum is σ = 20660670. Its totient is φ = 20660668.

The previous prime is 20660659. The next prime is 20660677. The reversal of 20660669 is 96606602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13235044 + 7425625 = 3638^2 + 2725^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20660669 is a prime.

It is a super-2 number, since 2×20660669² = 853726487055122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20660659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10330334 + 10330335.

It is an arithmetic number, because the mean of its divisors is an integer number (10330335).

Almost surely, 2^20660669 is an apocalyptic number.

It is an amenable number.

20660669 is a deficient number, since it is larger than the sum of its proper divisors (1).

20660669 is an equidigital number, since it uses as much as digits as its factorization.

20660669 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 35.

The square root of 20660669 is about 4545.4008624103. The cubic root of 20660669 is about 274.3983275362.

The spelling of 20660669 in words is "twenty million, six hundred sixty thousand, six hundred sixty-nine".