31109420791 has 4 divisors (see below), whose sum is σ = 31318209000. Its totient is φ = 30900632584.

The previous prime is 31109420779. The next prime is 31109420833. The reversal of 31109420791 is 19702490113.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19702490113 = 193 ⋅102085441.

It is a cyclic number.

It is not a de Polignac number, because 31109420791 - 2⁷ = 31109420663 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31109420791.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31109423791) 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, 104393881 + ... + 104394178.

It is an arithmetic number, because the mean of its divisors is an integer number (7829552250).

Almost surely, 2^31109420791 is an apocalyptic number.

31109420791 is a deficient number, since it is larger than the sum of its proper divisors (208788209).

31109420791 is a wasteful number, since it uses less digits than its factorization.

31109420791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208788208.

The product of its (nonzero) digits is 13608, while the sum is 37.

The spelling of 31109420791 in words is "thirty-one billion, one hundred nine million, four hundred twenty thousand, seven hundred ninety-one".