91721459 has 8 divisors (see below), whose sum is σ = 94672320. Its totient is φ = 88817256.

The previous prime is 91721437. The next prime is 91721471. The reversal of 91721459 is 95412719.

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

It is a cyclic number.

It is not a de Polignac number, because 91721459 - 2¹⁶ = 91655923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91721159) 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, 7649 + ... + 15554.

It is an arithmetic number, because the mean of its divisors is an integer number (11834040).

Almost surely, 2^91721459 is an apocalyptic number.

91721459 is a deficient number, since it is larger than the sum of its proper divisors (2950861).

91721459 is a wasteful number, since it uses less digits than its factorization.

91721459 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23329.

The product of its digits is 22680, while the sum is 38.

The square root of 91721459 is about 9577.1320863816. The cubic root of 91721459 is about 450.9796910896.

The spelling of 91721459 in words is "ninety-one million, seven hundred twenty-one thousand, four hundred fifty-nine".