91000099000020 has 192 divisors, whose sum is σ = 294771686307840. Its totient is φ = 20545031849472.

The previous prime is 91000099000007. The next prime is 91000099000043. The reversal of 91000099000020 is 2000099000019.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 164367426 + ... + 164920134.

It is an arithmetic number, because the mean of its divisors is an integer number (1535269199520).

Almost surely, 2^{91000099000020} 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 91000099000020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147385843153920).

91000099000020 is an abundant number, since it is smaller than the sum of its proper divisors (203771587307820).

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

91000099000020 is a wasteful number, since it uses less digits than its factorization.

91000099000020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 557534 (or 557532 counting only the distinct ones).

The product of its (nonzero) digits is 1458, while the sum is 30.

The spelling of 91000099000020 in words is "ninety-one trillion, ninety-nine million, twenty", and thus it is an aban number and an uban number.