21120031031 has 6 divisors (see below), whose sum is σ = 23214579696. Its totient is φ = 19200028100.

The previous prime is 21120031007. The next prime is 21120031033. The reversal of 21120031031 is 13013002112.

It is not a de Polignac number, because 21120031031 - 2¹⁴ = 21120014647 is a prime.

It is a super-2 number, since 2×21120031031² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21120030997 and 21120031015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120031033) 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 5 ways as a sum of consecutive naturals, for example, 87272735 + ... + 87272976.

It is an arithmetic number, because the mean of its divisors is an integer number (3869096616).

Almost surely, 2^21120031031 is an apocalyptic number.

21120031031 is a deficient number, since it is larger than the sum of its proper divisors (2094548665).

21120031031 is a wasteful number, since it uses less digits than its factorization.

21120031031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174545733 (or 174545722 counting only the distinct ones).

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

Adding to 21120031031 its reverse (13013002112), we get a palindrome (34133033143).

The spelling of 21120031031 in words is "twenty-one billion, one hundred twenty million, thirty-one thousand, thirty-one".