20664266501 has 4 divisors (see below), whose sum is σ = 20669755872. Its totient is φ = 20658777132.

The previous prime is 20664266461. The next prime is 20664266503. The reversal of 20664266501 is 10566246602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 10566246602 = 2 ⋅5283123301.

It is a cyclic number.

It is not a de Polignac number, because 20664266501 - 2⁶ = 20664266437 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20664266503) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2739035 + ... + 2746568.

It is an arithmetic number, because the mean of its divisors is an integer number (5167438968).

Almost surely, 2^20664266501 is an apocalyptic number.

It is an amenable number.

20664266501 is a deficient number, since it is larger than the sum of its proper divisors (5489371).

20664266501 is an equidigital number, since it uses as much as digits as its factorization.

20664266501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5489370.

The product of its (nonzero) digits is 103680, while the sum is 38.

The spelling of 20664266501 in words is "twenty billion, six hundred sixty-four million, two hundred sixty-six thousand, five hundred one".