91412720 has 80 divisors (see below), whose sum is σ = 244270080. Its totient is φ = 31164672.

The previous prime is 91412719. The next prime is 91412731. The reversal of 91412720 is 2721419.

It is a Cunningham number, because it is equal to 9561²-1.

It is a tau number, because it is divible by the number of its divisors (80).

It is a self number, because there is not a number n which added to its sum of digits gives 91412720.

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, 133499 + ... + 134181.

It is an arithmetic number, because the mean of its divisors is an integer number (3053376).

Almost surely, 2^91412720 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 91412720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122135040).

91412720 is an abundant number, since it is smaller than the sum of its proper divisors (152857360).

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

91412720 is a wasteful number, since it uses less digits than its factorization.

91412720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 942 (or 936 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 26.

The square root of 91412720 is about 9560.9999477042. Note that the first 4 decimals coincide. The cubic root of 91412720 is about 450.4731155758.

The spelling of 91412720 in words is "ninety-one million, four hundred twelve thousand, seven hundred twenty".