20011213031 has 4 divisors (see below), whose sum is σ = 20656736064. Its totient is φ = 19365690000.

The previous prime is 20011212973. The next prime is 20011213049. The reversal of 20011213031 is 13031211002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20011213031 is a prime.

It is a super-2 number, since 2×20011213031² (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 = 20011212997 and 20011213015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20011213051) 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, 322761470 + ... + 322761531.

It is an arithmetic number, because the mean of its divisors is an integer number (5164184016).

Almost surely, 2^20011213031 is an apocalyptic number.

20011213031 is a deficient number, since it is larger than the sum of its proper divisors (645523033).

20011213031 is an equidigital number, since it uses as much as digits as its factorization.

20011213031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645523032.

The product of its (nonzero) digits is 36, while the sum is 14.

Adding to 20011213031 its reverse (13031211002), we get a palindrome (33042424033).

The spelling of 20011213031 in words is "twenty billion, eleven million, two hundred thirteen thousand, thirty-one".