9130721 has 4 divisors (see below), whose sum is σ = 9136944. Its totient is φ = 9124500.

The previous prime is 9130691. The next prime is 9130729. The reversal of 9130721 is 1270319.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 9130721 - 2⁶ = 9130657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9130729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 446 + ... + 4296.

It is an arithmetic number, because the mean of its divisors is an integer number (2284236).

Almost surely, 2^9130721 is an apocalyptic number.

It is an amenable number.

9130721 is a deficient number, since it is larger than the sum of its proper divisors (6223).

9130721 is a wasteful number, since it uses less digits than its factorization.

9130721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6222.

The product of its (nonzero) digits is 378, while the sum is 23.

The square root of 9130721 is about 3021.7082916787. The cubic root of 9130721 is about 209.0106219276.

The spelling of 9130721 in words is "nine million, one hundred thirty thousand, seven hundred twenty-one".