31121100240 has 80 divisors (see below), whose sum is σ = 96497246400. Its totient is φ = 8297081856.

The previous prime is 31121100239. The next prime is 31121100247. The reversal of 31121100240 is 4200112113.

It is a tau number, because it is divible by the number of its divisors (80).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31121100247) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1288596 + ... + 1312524.

It is an arithmetic number, because the mean of its divisors is an integer number (1206215580).

Almost surely, 2^31121100240 is an apocalyptic number.

31121100240 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31121100240 is an abundant number, since it is smaller than the sum of its proper divisors (65376146160).

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

31121100240 is a wasteful number, since it uses less digits than its factorization.

31121100240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29364 (or 29358 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 31121100240 its reverse (4200112113), we get a palindrome (35321212353).

The spelling of 31121100240 in words is "thirty-one billion, one hundred twenty-one million, one hundred thousand, two hundred forty".