31791771648 has 702 divisors, whose sum is σ = 118009571784. Its totient is φ = 8384643072.

The previous prime is 31791771647. The next prime is 31791771673. The reversal of 31791771648 is 84617719713.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (702).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

Its product of digits (1778112) is a multiple of the sum of its prime factors (81).

It is a zygodrome in base 6.

It is a junction number, because it is equal to n+sod(n) for n = 31791771594 and 31791771603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31791771647) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 2445520890 + ... + 2445520902.

Almost surely, 2^31791771648 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31791771648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (59004785892).

31791771648 is an abundant number, since it is smaller than the sum of its proper divisors (86217800136).

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

31791771648 is an frugal number, since it uses more digits than its factorization.

31791771648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81 (or 25 counting only the distinct ones).

The product of its digits is 1778112, while the sum is 54.

The spelling of 31791771648 in words is "thirty-one billion, seven hundred ninety-one million, seven hundred seventy-one thousand, six hundred forty-eight".