31231120121111 has 4 divisors (see below), whose sum is σ = 32874863285400. Its totient is φ = 29587376956824.

The previous prime is 31231120121101. The next prime is 31231120121129. The reversal of 31231120121111 is 11112102113213.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 31231120121111 - 2¹⁴ = 31231120104727 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31231120121101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 821871582116 + ... + 821871582153.

It is an arithmetic number, because the mean of its divisors is an integer number (8218715821350).

Almost surely, 2^{31231120121111} is an apocalyptic number.

31231120121111 is a deficient number, since it is larger than the sum of its proper divisors (1643743164289).

31231120121111 is a wasteful number, since it uses less digits than its factorization.

31231120121111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1643743164288.

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

Adding to 31231120121111 its reverse (11112102113213), we get a palindrome (42343222234324).

The spelling of 31231120121111 in words is "thirty-one trillion, two hundred thirty-one billion, one hundred twenty million, one hundred twenty-one thousand, one hundred eleven".