90791710064640 has 2304 divisors, whose sum is σ = 360799602836400. Its totient is φ = 21794912206848.

The previous prime is 90791710064617. The next prime is 90791710064683. The reversal of 90791710064640 is 4646001719709.

90791710064640 is a `hidden beast` number, since 9 + 0 + 7 + 9 + 171 + 0 + 0 + 6 + 464 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 12943416508416 + 77848293556224 = 3597696^2 + 8823168^2 .

It is a tau number, because it is divible by the number of its divisors (2304).

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

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1020131573716 + ... + 1020131573804.

Almost surely, 2^{90791710064640} is an apocalyptic number.

90791710064640 is a gapful number since it is divisible by the number (90) 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 90791710064640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (180399801418200).

90791710064640 is an abundant number, since it is smaller than the sum of its proper divisors (270007892771760).

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

90791710064640 is an frugal number, since it uses more digits than its factorization.

90791710064640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234 (or 185 counting only the distinct ones).

The product of its (nonzero) digits is 2286144, while the sum is 54.

The spelling of 90791710064640 in words is "ninety trillion, seven hundred ninety-one billion, seven hundred ten million, sixty-four thousand, six hundred forty".