31705639680 has 864 divisors, whose sum is σ = 124682201280. Its totient is φ = 6812467200.

The previous prime is 31705639643. The next prime is 31705639681. The reversal of 31705639680 is 8693650713.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31705639681) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 175169190 + ... + 175169370.

Almost surely, 2^31705639680 is an apocalyptic number.

31705639680 is a gapful number since it is divisible by the number (30) 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 31705639680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62341100640).

31705639680 is an abundant number, since it is smaller than the sum of its proper divisors (92976561600).

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

31705639680 is a wasteful number, since it uses less digits than its factorization.

31705639680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269 (or 244 counting only the distinct ones).

The product of its (nonzero) digits is 816480, while the sum is 48.

The spelling of 31705639680 in words is "thirty-one billion, seven hundred five million, six hundred thirty-nine thousand, six hundred eighty".