20756815117 has 4 divisors (see below), whose sum is σ = 20816633376. Its totient is φ = 20696996860.

The previous prime is 20756815099. The next prime is 20756815141. The reversal of 20756815117 is 71151865702.

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 a cyclic number.

It is not a de Polignac number, because 20756815117 - 2¹⁹ = 20756290829 is a prime.

It is a super-3 number, since 3×20756815117³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20756815187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29908609 + ... + 29909302.

It is an arithmetic number, because the mean of its divisors is an integer number (5204158344).

Almost surely, 2^20756815117 is an apocalyptic number.

It is an amenable number.

20756815117 is a deficient number, since it is larger than the sum of its proper divisors (59818259).

20756815117 is an equidigital number, since it uses as much as digits as its factorization.

20756815117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59818258.

The product of its (nonzero) digits is 117600, while the sum is 43.

The spelling of 20756815117 in words is "twenty billion, seven hundred fifty-six million, eight hundred fifteen thousand, one hundred seventeen".