20636620469 has 2 divisors, whose sum is σ = 20636620470. Its totient is φ = 20636620468.

The previous prime is 20636620453. The next prime is 20636620471. The reversal of 20636620469 is 96402663602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20057640625 + 578979844 = 141625^2 + 24062^2 .

It is a cyclic number.

It is not a de Polignac number, because 20636620469 - 2⁴ = 20636620453 is a prime.

It is a super-2 number, since 2×20636620469² (a number of 21 digits) contains 22 as substring.

Together with 20636620471, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20636620489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10318310234 + 10318310235.

It is an arithmetic number, because the mean of its divisors is an integer number (10318310235).

Almost surely, 2^20636620469 is an apocalyptic number.

It is an amenable number.

20636620469 is a deficient number, since it is larger than the sum of its proper divisors (1).

20636620469 is an equidigital number, since it uses as much as digits as its factorization.

20636620469 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 559872, while the sum is 44.

The spelling of 20636620469 in words is "twenty billion, six hundred thirty-six million, six hundred twenty thousand, four hundred sixty-nine".