21111211002031 has 2 divisors, whose sum is σ = 21111211002032. Its totient is φ = 21111211002030.

The previous prime is 21111211001983. The next prime is 21111211002067. The reversal of 21111211002031 is 13020011211112.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21111211002031 - 2²⁵ = 21111177447599 is a prime.

It is a super-2 number, since 2×21111211002031² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21111211001996 and 21111211002014.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21111211006031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555605501015 + 10555605501016.

It is an arithmetic number, because the mean of its divisors is an integer number (10555605501016).

Almost surely, 2^{21111211002031} is an apocalyptic number.

21111211002031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111211002031 is an equidigital number, since it uses as much as digits as its factorization.

21111211002031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24, while the sum is 16.

Adding to 21111211002031 its reverse (13020011211112), we get a palindrome (34131222213143).

The spelling of 21111211002031 in words is "twenty-one trillion, one hundred eleven billion, two hundred eleven million, two thousand, thirty-one".