20440806497 has 2 divisors, whose sum is σ = 20440806498. Its totient is φ = 20440806496.

The previous prime is 20440806481. The next prime is 20440806527. The reversal of 20440806497 is 79460804402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19981518736 + 459287761 = 141356^2 + 21431^2 .

It is a cyclic number.

It is not a de Polignac number, because 20440806497 - 2⁴ = 20440806481 is a prime.

It is a super-2 number, since 2×20440806497² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20440806437) 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, 10220403248 + 10220403249.

It is an arithmetic number, because the mean of its divisors is an integer number (10220403249).

Almost surely, 2^20440806497 is an apocalyptic number.

It is an amenable number.

20440806497 is a deficient number, since it is larger than the sum of its proper divisors (1).

20440806497 is an equidigital number, since it uses as much as digits as its factorization.

20440806497 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 387072, while the sum is 44.

The spelling of 20440806497 in words is "twenty billion, four hundred forty million, eight hundred six thousand, four hundred ninety-seven".