31223987911 has 4 divisors (see below), whose sum is σ = 31250836872. Its totient is φ = 31197138952.

The previous prime is 31223987903. The next prime is 31223987917. The reversal of 31223987911 is 11978932213.

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 31223987911 - 2³ = 31223987903 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 (31223987917) 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, 13422736 + ... + 13425061.

It is an arithmetic number, because the mean of its divisors is an integer number (7812709218).

Almost surely, 2^31223987911 is an apocalyptic number.

31223987911 is a deficient number, since it is larger than the sum of its proper divisors (26848961).

31223987911 is a wasteful number, since it uses less digits than its factorization.

31223987911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26848960.

The product of its digits is 163296, while the sum is 46.

The spelling of 31223987911 in words is "thirty-one billion, two hundred twenty-three million, nine hundred eighty-seven thousand, nine hundred eleven".