91903731320520 has 1920 divisors, whose sum is σ = 380233098685440. Its totient is φ = 19924598453760.

The previous prime is 91903731320519. The next prime is 91903731320539. The reversal of 91903731320520 is 2502313730919.

91903731320520 is a `hidden beast` number, since 9 + 1 + 90 + 3 + 7 + 3 + 1 + 32 + 0 + 520 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 479 ways as a sum of consecutive naturals, for example, 70316549707 + ... + 70316551013.

It is an arithmetic number, because the mean of its divisors is an integer number (198038072232).

Almost surely, 2^{91903731320520} is an apocalyptic number.

91903731320520 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 91903731320520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (190116549342720).

91903731320520 is an abundant number, since it is smaller than the sum of its proper divisors (288329367364920).

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

91903731320520 is a wasteful number, since it uses less digits than its factorization.

91903731320520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1515 (or 1478 counting only the distinct ones).

The product of its (nonzero) digits is 306180, while the sum is 45.

The spelling of 91903731320520 in words is "ninety-one trillion, nine hundred three billion, seven hundred thirty-one million, three hundred twenty thousand, five hundred twenty".