31122121109 has 4 divisors (see below), whose sum is σ = 31164235680. Its totient is φ = 31080006540.

The previous prime is 31122121103. The next prime is 31122121117. The reversal of 31122121109 is 90112122113.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 90112122113 = 13 ⋅6931701701.

It is a cyclic number.

It is not a de Polignac number, because 31122121109 - 2⁸ = 31122120853 is a prime.

It is a super-3 number, since 3×31122121109³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31122121103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21056177 + ... + 21057654.

It is an arithmetic number, because the mean of its divisors is an integer number (7791058920).

Almost surely, 2^31122121109 is an apocalyptic number.

It is an amenable number.

31122121109 is a deficient number, since it is larger than the sum of its proper divisors (42114571).

31122121109 is an equidigital number, since it uses as much as digits as its factorization.

31122121109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42114570.

The product of its (nonzero) digits is 216, while the sum is 23.

The spelling of 31122121109 in words is "thirty-one billion, one hundred twenty-two million, one hundred twenty-one thousand, one hundred nine".