20669651 has 2 divisors, whose sum is σ = 20669652. Its totient is φ = 20669650.

The previous prime is 20669641. The next prime is 20669659. The reversal of 20669651 is 15696602.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20669651 - 2¹⁴ = 20653267 is a prime.

It is not a weakly prime, because it can be changed into another prime (20669659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10334825 + 10334826.

It is an arithmetic number, because the mean of its divisors is an integer number (10334826).

Almost surely, 2^20669651 is an apocalyptic number.

20669651 is a deficient number, since it is larger than the sum of its proper divisors (1).

20669651 is an equidigital number, since it uses as much as digits as its factorization.

20669651 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 20669651 is about 4546.3887867185. The cubic root of 20669651 is about 274.4380856664.

The spelling of 20669651 in words is "twenty million, six hundred sixty-nine thousand, six hundred fifty-one".