21111202072031 has 2 divisors, whose sum is σ = 21111202072032. Its totient is φ = 21111202072030.

The previous prime is 21111202072021. The next prime is 21111202072061. The reversal of 21111202072031 is 13027020211112.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21111202072031 - 2³⁸ = 20836324165087 is a prime.

It is a super-2 number, since 2×21111202072031² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21111202071988 and 21111202072006.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21111202072021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555601036015 + 10555601036016.

It is an arithmetic number, because the mean of its divisors is an integer number (10555601036016).

Almost surely, 2^{21111202072031} is an apocalyptic number.

21111202072031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111202072031 is an equidigital number, since it uses as much as digits as its factorization.

21111202072031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 336, while the sum is 23.

Adding to 21111202072031 its reverse (13027020211112), we get a palindrome (34138222283143).

The spelling of 21111202072031 in words is "twenty-one trillion, one hundred eleven billion, two hundred two million, seventy-two thousand, thirty-one".