31491097208 has 8 divisors (see below), whose sum is σ = 59045807280. Its totient is φ = 15745548600.

The previous prime is 31491097201. The next prime is 31491097247. The reversal of 31491097208 is 80279019413.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31491097201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1968193568 + ... + 1968193583.

It is an arithmetic number, because the mean of its divisors is an integer number (7380725910).

Almost surely, 2^31491097208 is an apocalyptic number.

It is an amenable number.

31491097208 is a deficient number, since it is larger than the sum of its proper divisors (27554710072).

31491097208 is a wasteful number, since it uses less digits than its factorization.

31491097208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3936387157 (or 3936387153 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 44.

The spelling of 31491097208 in words is "thirty-one billion, four hundred ninety-one million, ninety-seven thousand, two hundred eight".