31818128240 has 40 divisors (see below), whose sum is σ = 77193550368. Its totient is φ = 12173891840.

The previous prime is 31818128219. The next prime is 31818128249. The reversal of 31818128240 is 4282181813.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 31818128194 and 31818128203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31818128249) 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, 8644391 + ... + 8648070.

Almost surely, 2^31818128240 is an apocalyptic number.

It is an amenable number.

31818128240 is an abundant number, since it is smaller than the sum of its proper divisors (45375422128).

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

31818128240 is a wasteful number, since it uses less digits than its factorization.

31818128240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17292497 (or 17292491 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 38.

The spelling of 31818128240 in words is "thirty-one billion, eight hundred eighteen million, one hundred twenty-eight thousand, two hundred forty".