31223123011 has 4 divisors (see below), whose sum is σ = 31223701800. Its totient is φ = 31222544224.

The previous prime is 31223122991. The next prime is 31223123017. The reversal of 31223123011 is 11032132213.

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 31223123011 - 2⁵ = 31223122979 is a prime.

It is a super-2 number, since 2×31223123011² (a number of 22 digits) contains 22 as substring.

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 31223123011.

It is not an unprimeable number, because it can be changed into a prime (31223123017) 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, 199081 + ... + 319498.

It is an arithmetic number, because the mean of its divisors is an integer number (7805925450).

Almost surely, 2^31223123011 is an apocalyptic number.

31223123011 is a deficient number, since it is larger than the sum of its proper divisors (578789).

31223123011 is an equidigital number, since it uses as much as digits as its factorization.

31223123011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 578788.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 31223123011 its reverse (11032132213), we get a palindrome (42255255224).

The spelling of 31223123011 in words is "thirty-one billion, two hundred twenty-three million, one hundred twenty-three thousand, eleven".