20211100031 has 4 divisors (see below), whose sum is σ = 20246128512. Its totient is φ = 20176071552.

The previous prime is 20211100009. The next prime is 20211100057. The reversal of 20211100031 is 13000111202.

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 20211100031 - 2¹⁴ = 20211083647 is a prime.

It is a super-2 number, since 2×20211100031² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20211099985 and 20211100021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20211100331) 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, 17513375 + ... + 17514528.

It is an arithmetic number, because the mean of its divisors is an integer number (5061532128).

Almost surely, 2^20211100031 is an apocalyptic number.

20211100031 is a deficient number, since it is larger than the sum of its proper divisors (35028481).

20211100031 is an equidigital number, since it uses as much as digits as its factorization.

20211100031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35028480.

The product of its (nonzero) digits is 12, while the sum is 11.

Adding to 20211100031 its reverse (13000111202), we get a palindrome (33211211233).

The spelling of 20211100031 in words is "twenty billion, two hundred eleven million, one hundred thousand, thirty-one".