21112031 has 2 divisors, whose sum is σ = 21112032. Its totient is φ = 21112030.

The previous prime is 21112019. The next prime is 21112037. The reversal of 21112031 is 13021112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21112031 - 2¹⁰ = 21111007 is a prime.

It is a super-2 number, since 2×21112031² = 891435705889922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21112037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556015 + 10556016.

It is an arithmetic number, because the mean of its divisors is an integer number (10556016).

Almost surely, 2^21112031 is an apocalyptic number.

21112031 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112031 is an equidigital number, since it uses as much as digits as its factorization.

21112031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 21112031 is about 4594.7830199042. The cubic root of 21112031 is about 276.3821589414.

Adding to 21112031 its reverse (13021112), we get a palindrome (34133143).

The spelling of 21112031 in words is "twenty-one million, one hundred twelve thousand, thirty-one".