20440667497 has 2 divisors, whose sum is σ = 20440667498. Its totient is φ = 20440667496.

The previous prime is 20440667461. The next prime is 20440667521. The reversal of 20440667497 is 79476604402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17953052121 + 2487615376 = 133989^2 + 49876^2 .

It is a cyclic number.

It is not a de Polignac number, because 20440667497 - 2⁷ = 20440667369 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20440667497.

It is not a weakly prime, because it can be changed into another prime (20440607497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10220333748 + 10220333749.

It is an arithmetic number, because the mean of its divisors is an integer number (10220333749).

Almost surely, 2^20440667497 is an apocalyptic number.

It is an amenable number.

20440667497 is a deficient number, since it is larger than the sum of its proper divisors (1).

20440667497 is an equidigital number, since it uses as much as digits as its factorization.

20440667497 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2032128, while the sum is 49.

The spelling of 20440667497 in words is "twenty billion, four hundred forty million, six hundred sixty-seven thousand, four hundred ninety-seven".