91721748 has 24 divisors (see below), whose sum is σ = 215218080. Its totient is φ = 30402400.

The previous prime is 91721719. The next prime is 91721753. The reversal of 91721748 is 84712719.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19203 + ... + 23498.

It is an arithmetic number, because the mean of its divisors is an integer number (8967420).

Almost surely, 2^91721748 is an apocalyptic number.

It is an amenable number.

91721748 is an abundant number, since it is smaller than the sum of its proper divisors (123496332).

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

91721748 is a wasteful number, since it uses less digits than its factorization.

91721748 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42887 (or 42885 counting only the distinct ones).

The product of its digits is 28224, while the sum is 39.

The square root of 91721748 is about 9577.1471743938. The cubic root of 91721748 is about 450.9801647447.

The spelling of 91721748 in words is "ninety-one million, seven hundred twenty-one thousand, seven hundred forty-eight".