20156718031 has 4 divisors (see below), whose sum is σ = 20701494232. Its totient is φ = 19611941832.

The previous prime is 20156718019. The next prime is 20156718037. The reversal of 20156718031 is 13081765102.

It is a happy number.

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 20156718031 - 2⁹ = 20156717519 is a prime.

It is a super-2 number, since 2×20156718031² (a number of 21 digits) contains 22 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 (20156718037) 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, 272388045 + ... + 272388118.

It is an arithmetic number, because the mean of its divisors is an integer number (5175373558).

Almost surely, 2^20156718031 is an apocalyptic number.

20156718031 is a deficient number, since it is larger than the sum of its proper divisors (544776201).

20156718031 is an equidigital number, since it uses as much as digits as its factorization.

20156718031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 544776200.

The product of its (nonzero) digits is 10080, while the sum is 34.

The spelling of 20156718031 in words is "twenty billion, one hundred fifty-six million, seven hundred eighteen thousand, thirty-one".