9720091 has 4 divisors (see below), whose sum is σ = 9749272. Its totient is φ = 9690912.

The previous prime is 9720089. The next prime is 9720097. The reversal of 9720091 is 1900279.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1900279 = 431 ⋅4409.

It is a cyclic number.

It is not a de Polignac number, because 9720091 - 2¹ = 9720089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9720097) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14085 + ... + 14758.

It is an arithmetic number, because the mean of its divisors is an integer number (2437318).

Almost surely, 2^9720091 is an apocalyptic number.

9720091 is a deficient number, since it is larger than the sum of its proper divisors (29181).

9720091 is a wasteful number, since it uses less digits than its factorization.

9720091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29180.

The product of its (nonzero) digits is 1134, while the sum is 28.

The square root of 9720091 is about 3117.7060477216. The cubic root of 9720091 is about 213.4142642700.

The spelling of 9720091 in words is "nine million, seven hundred twenty thousand, ninety-one".