9127721 has 8 divisors (see below), whose sum is σ = 9477000. Its totient is φ = 8780800.

The previous prime is 9127717. The next prime is 9127753. The reversal of 9127721 is 1277219.

It can be written as a sum of positive squares in 4 ways, for example, as 3463321 + 5664400 = 1861^2 + 2380^2 .

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

It is a 4-Lehmer number, since φ(9127721) divides (9127721-1)⁴.

It is a cyclic number.

It is not a de Polignac number, because 9127721 - 2² = 9127717 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (9127621) 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 7 ways as a sum of consecutive naturals, for example, 12671 + ... + 13371.

It is an arithmetic number, because the mean of its divisors is an integer number (1184625).

Almost surely, 2^9127721 is an apocalyptic number.

It is an amenable number.

9127721 is a deficient number, since it is larger than the sum of its proper divisors (349279).

9127721 is a wasteful number, since it uses less digits than its factorization.

9127721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1179.

The product of its digits is 1764, while the sum is 29.

The square root of 9127721 is about 3021.2118429531. The cubic root of 9127721 is about 208.9877284981.

The spelling of 9127721 in words is "nine million, one hundred twenty-seven thousand, seven hundred twenty-one".