20664747727501 has 2 divisors, whose sum is σ = 20664747727502. Its totient is φ = 20664747727500.

The previous prime is 20664747727451. The next prime is 20664747727583. The reversal of 20664747727501 is 10572774746602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13767290784900 + 6897456942601 = 3710430^2 + 2626301^2 .

It is a cyclic number.

It is not a de Polignac number, because 20664747727501 - 2¹⁹ = 20664747203213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20664747727601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10332373863750 + 10332373863751.

It is an arithmetic number, because the mean of its divisors is an integer number (10332373863751).

Almost surely, 2^{20664747727501} is an apocalyptic number.

It is an amenable number.

20664747727501 is a deficient number, since it is larger than the sum of its proper divisors (1).

20664747727501 is an equidigital number, since it uses as much as digits as its factorization.

20664747727501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27659520, while the sum is 58.

The spelling of 20664747727501 in words is "twenty trillion, six hundred sixty-four billion, seven hundred forty-seven million, seven hundred twenty-seven thousand, five hundred one".