20664601 has 2 divisors, whose sum is σ = 20664602. Its totient is φ = 20664600.

The previous prime is 20664587. The next prime is 20664641. The reversal of 20664601 is 10646602.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20466576 + 198025 = 4524^2 + 445^2 .

It is a cyclic number.

It is not a de Polignac number, because 20664601 - 2⁷ = 20664473 is a prime.

It is not a weakly prime, because it can be changed into another prime (20664641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10332300 + 10332301.

It is an arithmetic number, because the mean of its divisors is an integer number (10332301).

Almost surely, 2^20664601 is an apocalyptic number.

It is an amenable number.

20664601 is a deficient number, since it is larger than the sum of its proper divisors (1).

20664601 is an equidigital number, since it uses as much as digits as its factorization.

20664601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 20664601 is about 4545.8333669416. The cubic root of 20664601 is about 274.4157336486.

The spelling of 20664601 in words is "twenty million, six hundred sixty-four thousand, six hundred one".