20666574591 has 32 divisors (see below), whose sum is σ = 30331542528. Its totient is φ = 12437001600.

The previous prime is 20666574571. The next prime is 20666574601. The reversal of 20666574591 is 19547566602.

It is not a de Polignac number, because 20666574591 - 2⁶ = 20666574527 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20666574571) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2611741 + ... + 2619641.

It is an arithmetic number, because the mean of its divisors is an integer number (947860704).

Almost surely, 2^20666574591 is an apocalyptic number.

20666574591 is a deficient number, since it is larger than the sum of its proper divisors (9664967937).

20666574591 is a wasteful number, since it uses less digits than its factorization.

20666574591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9391.

The product of its (nonzero) digits is 2721600, while the sum is 51.

The spelling of 20666574591 in words is "twenty billion, six hundred sixty-six million, five hundred seventy-four thousand, five hundred ninety-one".