111212021 has 2 divisors, whose sum is σ = 111212022. Its totient is φ = 111212020.

The previous prime is 111211999. The next prime is 111212041. The reversal of 111212021 is 120212111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76755121 + 34456900 = 8761^2 + 5870^2 .

It is a cyclic number.

It is not a de Polignac number, because 111212021 - 2¹⁰ = 111210997 is a prime.

It is a super-2 number, since 2×111212021² = 24736227229808882, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 111211993 and 111212011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111212041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55606010 + 55606011.

It is an arithmetic number, because the mean of its divisors is an integer number (55606011).

Almost surely, 2^111212021 is an apocalyptic number.

It is an amenable number.

111212021 is a deficient number, since it is larger than the sum of its proper divisors (1).

111212021 is an equidigital number, since it uses as much as digits as its factorization.

111212021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 111212021 is about 10545.7110239187. The cubic root of 111212021 is about 480.8953499768.

Adding to 111212021 its reverse (120212111), we get a palindrome (231424132).

The spelling of 111212021 in words is "one hundred eleven million, two hundred twelve thousand, twenty-one".