20356478369 has 2 divisors, whose sum is σ = 20356478370. Its totient is φ = 20356478368.

The previous prime is 20356478347. The next prime is 20356478407. The reversal of 20356478369 is 96387465302.

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., 14868631969 + 5487846400 = 121937^2 + 74080^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20356478369 is a prime.

It is a super-2 number, since 2×20356478369² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20356478369.

It is not a weakly prime, because it can be changed into another prime (20356478309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10178239184 + 10178239185.

It is an arithmetic number, because the mean of its divisors is an integer number (10178239185).

Almost surely, 2^20356478369 is an apocalyptic number.

It is an amenable number.

20356478369 is a deficient number, since it is larger than the sum of its proper divisors (1).

20356478369 is an equidigital number, since it uses as much as digits as its factorization.

20356478369 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6531840, while the sum is 53.

The spelling of 20356478369 in words is "twenty billion, three hundred fifty-six million, four hundred seventy-eight thousand, three hundred sixty-nine".