20405669597 has 4 divisors (see below), whose sum is σ = 20460376860. Its totient is φ = 20350962336.

The previous prime is 20405669579. The next prime is 20405669623. The reversal of 20405669597 is 79596650402.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16217767801 + 4187901796 = 127349^2 + 64714^2 .

It is a cyclic number.

It is not a de Polignac number, because 20405669597 - 2¹⁸ = 20405407453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20405669567) 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 in 3 ways as a sum of consecutive naturals, for example, 27353072 + ... + 27353817.

It is an arithmetic number, because the mean of its divisors is an integer number (5115094215).

Almost surely, 2^20405669597 is an apocalyptic number.

It is an amenable number.

20405669597 is a deficient number, since it is larger than the sum of its proper divisors (54707263).

20405669597 is an equidigital number, since it uses as much as digits as its factorization.

20405669597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54707262.

The product of its (nonzero) digits is 4082400, while the sum is 53.

The spelling of 20405669597 in words is "twenty billion, four hundred five million, six hundred sixty-nine thousand, five hundred ninety-seven".