31123120200 has 96 divisors (see below), whose sum is σ = 96629306400. Its totient is φ = 8286799360.

The previous prime is 31123120187. The next prime is 31123120201. The reversal of 31123120200 is 202132113.

It is a super-2 number, since 2×31123120200² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 31123120200.

It is not an unprimeable number, because it can be changed into a prime (31123120201) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 356044 + ... + 434756.

It is an arithmetic number, because the mean of its divisors is an integer number (1006555275).

Almost surely, 2^31123120200 is an apocalyptic number.

31123120200 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 31123120200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48314653200).

31123120200 is an abundant number, since it is smaller than the sum of its proper divisors (65506186200).

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

31123120200 is a wasteful number, since it uses less digits than its factorization.

31123120200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79391 (or 79382 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 31123120200 its reverse (202132113), we get a palindrome (31325252313).

The spelling of 31123120200 in words is "thirty-one billion, one hundred twenty-three million, one hundred twenty thousand, two hundred".