91091759021 has 8 divisors (see below), whose sum is σ = 95139356640. Its totient is φ = 87127617168.

The previous prime is 91091758997. The next prime is 91091759023. The reversal of 91091759021 is 12095719019.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 91091759021 - 2¹⁸ = 91091496877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91091759023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20861711 + ... + 20866076.

It is an arithmetic number, because the mean of its divisors is an integer number (11892419580).

Almost surely, 2^91091759021 is an apocalyptic number.

It is an amenable number.

91091759021 is a deficient number, since it is larger than the sum of its proper divisors (4047597619).

91091759021 is a wasteful number, since it uses less digits than its factorization.

91091759021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41727883.

The product of its (nonzero) digits is 51030, while the sum is 44.

The spelling of 91091759021 in words is "ninety-one billion, ninety-one million, seven hundred fifty-nine thousand, twenty-one".