20786687157 has 4 divisors (see below), whose sum is σ = 27715582880. Its totient is φ = 13857791436.

The previous prime is 20786687137. The next prime is 20786687183. The reversal of 20786687157 is 75178668702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 20786687157 - 2¹⁰ = 20786686133 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20786687097 and 20786687106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20786687137) 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, 3464447857 + ... + 3464447862.

It is an arithmetic number, because the mean of its divisors is an integer number (6928895720).

Almost surely, 2^20786687157 is an apocalyptic number.

It is an amenable number.

20786687157 is a deficient number, since it is larger than the sum of its proper divisors (6928895723).

20786687157 is an equidigital number, since it uses as much as digits as its factorization.

20786687157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6928895722.

The product of its (nonzero) digits is 7902720, while the sum is 57.

The spelling of 20786687157 in words is "twenty billion, seven hundred eighty-six million, six hundred eighty-seven thousand, one hundred fifty-seven".