20506266413 has 2 divisors, whose sum is σ = 20506266414. Its totient is φ = 20506266412.

The previous prime is 20506266367. The next prime is 20506266419. The reversal of 20506266413 is 31466260502.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18241743844 + 2264522569 = 135062^2 + 47587^2 .

It is a cyclic number.

It is not a de Polignac number, because 20506266413 - 2¹⁰ = 20506265389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20506266419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10253133206 + 10253133207.

It is an arithmetic number, because the mean of its divisors is an integer number (10253133207).

Almost surely, 2^20506266413 is an apocalyptic number.

It is an amenable number.

20506266413 is a deficient number, since it is larger than the sum of its proper divisors (1).

20506266413 is an equidigital number, since it uses as much as digits as its factorization.

20506266413 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51840, while the sum is 35.

The spelling of 20506266413 in words is "twenty billion, five hundred six million, two hundred sixty-six thousand, four hundred thirteen".