31101121021 has 4 divisors (see below), whose sum is σ = 32173573500. Its totient is φ = 30028668544.

The previous prime is 31101120997. The next prime is 31101121031. The reversal of 31101121021 is 12012110113.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12012110113 = 31 ⋅387487423.

It can be written as a sum of positive squares in 2 ways, for example, as 25516548121 + 5584572900 = 159739^2 + 74730^2 .

It is a cyclic number.

It is not a de Polignac number, because 31101121021 - 2¹¹ = 31101118973 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31101120992 and 31101121010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31101121031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 536226196 + ... + 536226253.

It is an arithmetic number, because the mean of its divisors is an integer number (8043393375).

Almost surely, 2^31101121021 is an apocalyptic number.

It is an amenable number.

31101121021 is a deficient number, since it is larger than the sum of its proper divisors (1072452479).

31101121021 is a wasteful number, since it uses less digits than its factorization.

31101121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1072452478.

The product of its (nonzero) digits is 12, while the sum is 13.

Adding to 31101121021 its reverse (12012110113), we get a palindrome (43113231134).

The spelling of 31101121021 in words is "thirty-one billion, one hundred one million, one hundred twenty-one thousand, twenty-one".