91991804910 has 32 divisors (see below), whose sum is σ = 220815178272. Its totient is φ = 24527276160.

The previous prime is 91991804909. The next prime is 91991804929. The reversal of 91991804910 is 1940819919.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46149 + ... + 431408.

It is an arithmetic number, because the mean of its divisors is an integer number (6900474321).

Almost surely, 2^91991804910 is an apocalyptic number.

91991804910 is an abundant number, since it is smaller than the sum of its proper divisors (128823373362).

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

91991804910 is a wasteful number, since it uses less digits than its factorization.

91991804910 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 483988.

The product of its (nonzero) digits is 209952, while the sum is 51.

The spelling of 91991804910 in words is "ninety-one billion, nine hundred ninety-one million, eight hundred four thousand, nine hundred ten".