31111121321021 has 16 divisors (see below), whose sum is σ = 35681991744000. Its totient is φ = 26571861185328.

The previous prime is 31111121320991. The next prime is 31111121321029. The reversal of 31111121321021 is 12012312111113.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31111121321021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31111121320984 and 31111121321002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31111121321029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 106231490 + ... + 106523948.

It is an arithmetic number, because the mean of its divisors is an integer number (2230124484000).

Almost surely, 2^{31111121321021} is an apocalyptic number.

It is an amenable number.

31111121321021 is a deficient number, since it is larger than the sum of its proper divisors (4570870422979).

31111121321021 is a wasteful number, since it uses less digits than its factorization.

31111121321021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346448.

The product of its (nonzero) digits is 72, while the sum is 20.

Adding to 31111121321021 its reverse (12012312111113), we get a palindrome (43123433432134).

The spelling of 31111121321021 in words is "thirty-one trillion, one hundred eleven billion, one hundred twenty-one million, three hundred twenty-one thousand, twenty-one".