212121031 has 2 divisors, whose sum is σ = 212121032. Its totient is φ = 212121030.

The previous prime is 212121029. The next prime is 212121067. The reversal of 212121031 is 130121212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 212121031 - 2¹ = 212121029 is a prime.

It is a super-3 number, since 3×212121031³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 212121029, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212128031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106060515 + 106060516.

It is an arithmetic number, because the mean of its divisors is an integer number (106060516).

Almost surely, 2^212121031 is an apocalyptic number.

212121031 is a deficient number, since it is larger than the sum of its proper divisors (1).

212121031 is an equidigital number, since it uses as much as digits as its factorization.

212121031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 212121031 is about 14564.3754071364. The cubic root of 212121031 is about 596.3866451643.

Adding to 212121031 its reverse (130121212), we get a palindrome (342242243).

The spelling of 212121031 in words is "two hundred twelve million, one hundred twenty-one thousand, thirty-one".