20731797587 has 4 divisors (see below), whose sum is σ = 20742181056. Its totient is φ = 20721414120.

The previous prime is 20731797563. The next prime is 20731797589. The reversal of 20731797587 is 78579713702.

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 20731797587 - 2¹⁰ = 20731796563 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20731797589) 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, 5188739 + ... + 5192732.

It is an arithmetic number, because the mean of its divisors is an integer number (5185545264).

Almost surely, 2^20731797587 is an apocalyptic number.

20731797587 is a deficient number, since it is larger than the sum of its proper divisors (10383469).

20731797587 is a wasteful number, since it uses less digits than its factorization.

20731797587 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10383468.

The product of its (nonzero) digits is 5186160, while the sum is 56.

The spelling of 20731797587 in words is "twenty billion, seven hundred thirty-one million, seven hundred ninety-seven thousand, five hundred eighty-seven".