20740768591 has 4 divisors (see below), whose sum is σ = 20761083784. Its totient is φ = 20720453400.

The previous prime is 20740768589. The next prime is 20740768681. The reversal of 20740768591 is 19586704702.

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

It is a cyclic number.

It is not a de Polignac number, because 20740768591 - 2¹ = 20740768589 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 (20740718591) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10156065 + ... + 10158106.

It is an arithmetic number, because the mean of its divisors is an integer number (5190270946).

Almost surely, 2^20740768591 is an apocalyptic number.

20740768591 is a deficient number, since it is larger than the sum of its proper divisors (20315193).

20740768591 is a wasteful number, since it uses less digits than its factorization.

20740768591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20315192.

The product of its (nonzero) digits is 846720, while the sum is 49.

The spelling of 20740768591 in words is "twenty billion, seven hundred forty million, seven hundred sixty-eight thousand, five hundred ninety-one".