20461564369 has 2 divisors, whose sum is σ = 20461564370. Its totient is φ = 20461564368.

The previous prime is 20461564367. The next prime is 20461564421. The reversal of 20461564369 is 96346516402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19206633744 + 1254930625 = 138588^2 + 35425^2 .

It is a cyclic number.

It is not a de Polignac number, because 20461564369 - 2¹ = 20461564367 is a prime.

It is a super-2 number, since 2×20461564369² (a number of 21 digits) contains 22 as substring.

Together with 20461564367, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20461564367) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10230782184 + 10230782185.

It is an arithmetic number, because the mean of its divisors is an integer number (10230782185).

Almost surely, 2^20461564369 is an apocalyptic number.

It is an amenable number.

20461564369 is a deficient number, since it is larger than the sum of its proper divisors (1).

20461564369 is an equidigital number, since it uses as much as digits as its factorization.

20461564369 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 933120, while the sum is 46.

The spelling of 20461564369 in words is "twenty billion, four hundred sixty-one million, five hundred sixty-four thousand, three hundred sixty-nine".