21115103031 has 16 divisors (see below), whose sum is σ = 34125419520. Its totient is φ = 12797031960.

The previous prime is 21115103021. The next prime is 21115103039. The reversal of 21115103031 is 13030151112.

21115103031 is a `hidden beast` number, since 211 + 151 + 0 + 303 + 1 = 666.

It is not a de Polignac number, because 21115103031 - 2⁵ = 21115102999 is a prime.

It is a super-2 number, since 2×21115103031² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21115102995 and 21115103013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21115103039) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35547015 + ... + 35547608.

It is an arithmetic number, because the mean of its divisors is an integer number (2132838720).

Almost surely, 2^21115103031 is an apocalyptic number.

21115103031 is a deficient number, since it is larger than the sum of its proper divisors (13010316489).

21115103031 is a wasteful number, since it uses less digits than its factorization.

21115103031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71094643 (or 71094637 counting only the distinct ones).

The product of its (nonzero) digits is 90, while the sum is 18.

Adding to 21115103031 its reverse (13030151112), we get a palindrome (34145254143).

The spelling of 21115103031 in words is "twenty-one billion, one hundred fifteen million, one hundred three thousand, thirty-one".