21110311031 has 2 divisors, whose sum is σ = 21110311032. Its totient is φ = 21110311030.

The previous prime is 21110311009. The next prime is 21110311037. The reversal of 21110311031 is 13011301112.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21110311031 - 2¹⁸ = 21110048887 is a prime.

It is a super-2 number, since 2×21110311031² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21110310997 and 21110311015.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21110311037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555155515 + 10555155516.

It is an arithmetic number, because the mean of its divisors is an integer number (10555155516).

Almost surely, 2^21110311031 is an apocalyptic number.

21110311031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110311031 is an equidigital number, since it uses as much as digits as its factorization.

21110311031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18, while the sum is 14.

Adding to 21110311031 its reverse (13011301112), we get a palindrome (34121612143).

The spelling of 21110311031 in words is "twenty-one billion, one hundred ten million, three hundred eleven thousand, thirty-one".