21001113031 has 2 divisors, whose sum is σ = 21001113032. Its totient is φ = 21001113030.

The previous prime is 21001112999. The next prime is 21001113109. The reversal of 21001113031 is 13031110012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21001113031 - 2⁵ = 21001112999 is a prime.

It is a super-2 number, since 2×21001113031² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21001113131) 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 as a sum of consecutive naturals, namely, 10500556515 + 10500556516.

It is an arithmetic number, because the mean of its divisors is an integer number (10500556516).

Almost surely, 2^21001113031 is an apocalyptic number.

21001113031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001113031 is an equidigital number, since it uses as much as digits as its factorization.

21001113031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18, while the sum is 13.

Adding to 21001113031 its reverse (13031110012), we get a palindrome (34032223043).

The spelling of 21001113031 in words is "twenty-one billion, one million, one hundred thirteen thousand, thirty-one".