31123231020 has 216 divisors, whose sum is σ = 113888842704. Its totient is φ = 7113826944.

The previous prime is 31123231003. The next prime is 31123231081. The reversal of 31123231020 is 2013232113.

31123231020 is a `hidden beast` number, since 311 + 2 + 323 + 10 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 31123230984 and 31123231002.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 172794 + ... + 303486.

Almost surely, 2^31123231020 is an apocalyptic number.

31123231020 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31123231020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (56944421352).

31123231020 is an abundant number, since it is smaller than the sum of its proper divisors (82765611684).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31123231020 is a wasteful number, since it uses less digits than its factorization.

31123231020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130731 (or 130710 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 31123231020 its reverse (2013232113), we get a palindrome (33136463133).

The spelling of 31123231020 in words is "thirty-one billion, one hundred twenty-three million, two hundred thirty-one thousand, twenty".