31678391668 has 144 divisors (see below), whose sum is σ = 77289730560. Its totient is φ = 11004249600.

The previous prime is 31678391663. The next prime is 31678391681. The reversal of 31678391668 is 86619387613.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31678391663) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1681863 + ... + 1700593.

It is an arithmetic number, because the mean of its divisors is an integer number (536734240).

Almost surely, 2^31678391668 is an apocalyptic number.

31678391668 is a gapful number since it is divisible by the number (38) 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 31678391668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38644865280).

31678391668 is an abundant number, since it is smaller than the sum of its proper divisors (45611338892).

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

31678391668 is a wasteful number, since it uses less digits than its factorization.

31678391668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18806 (or 18787 counting only the distinct ones).

The product of its digits is 7838208, while the sum is 58.

The spelling of 31678391668 in words is "thirty-one billion, six hundred seventy-eight million, three hundred ninety-one thousand, six hundred sixty-eight".