20855818731 has 32 divisors (see below), whose sum is σ = 31050220032. Its totient is φ = 12345557760.

The previous prime is 20855818703. The next prime is 20855818751. The reversal of 20855818731 is 13781855802.

It is not a de Polignac number, because 20855818731 - 2⁶ = 20855818667 is a prime.

It is a super-2 number, since 2×20855818731² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20855818751) 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 31 ways as a sum of consecutive naturals, for example, 206101 + ... + 290153.

It is an arithmetic number, because the mean of its divisors is an integer number (970319376).

Almost surely, 2^20855818731 is an apocalyptic number.

20855818731 is a deficient number, since it is larger than the sum of its proper divisors (10194401301).

20855818731 is a wasteful number, since it uses less digits than its factorization.

20855818731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84243.

The product of its (nonzero) digits is 537600, while the sum is 48.

The spelling of 20855818731 in words is "twenty billion, eight hundred fifty-five million, eight hundred eighteen thousand, seven hundred thirty-one".