31123221999 has 8 divisors (see below), whose sum is σ = 41535600432. Its totient is φ = 20729829120.

The previous prime is 31123221989. The next prime is 31123222019. The reversal of 31123221999 is 99912232113.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-31123221999 is a prime.

It is a super-4 number, since 4×31123221999⁴ (a number of 43 digits) contains 4444 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31123221999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31123221919) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4742562 + ... + 4749119.

It is an arithmetic number, because the mean of its divisors is an integer number (5191950054).

Almost surely, 2^31123221999 is an apocalyptic number.

31123221999 is a deficient number, since it is larger than the sum of its proper divisors (10412378433).

31123221999 is a wasteful number, since it uses less digits than its factorization.

31123221999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9492777.

The product of its digits is 52488, while the sum is 42.

The spelling of 31123221999 in words is "thirty-one billion, one hundred twenty-three million, two hundred twenty-one thousand, nine hundred ninety-nine".