31728019081640 has 32 divisors (see below), whose sum is σ = 81586334782080. Its totient is φ = 10878177970752.

The previous prime is 31728019081637. The next prime is 31728019081673. The reversal of 31728019081640 is 4618091082713.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56657176652 + ... + 56657177211.

It is an arithmetic number, because the mean of its divisors is an integer number (2549572961940).

Almost surely, 2^{31728019081640} is an apocalyptic number.

It is an amenable number.

31728019081640 is an abundant number, since it is smaller than the sum of its proper divisors (49858315700440).

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

31728019081640 is a wasteful number, since it uses less digits than its factorization.

31728019081640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113314353881 (or 113314353877 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 50.

The spelling of 31728019081640 in words is "thirty-one trillion, seven hundred twenty-eight billion, nineteen million, eighty-one thousand, six hundred forty".