9142721 has 4 divisors (see below), whose sum is σ = 10448832. Its totient is φ = 7836612.

The previous prime is 9142711. The next prime is 9142723. The reversal of 9142721 is 1272419.

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 an emirpimes, since its reverse is a distinct semiprime: 1272419 = 389 ⋅3271.

It is not a de Polignac number, because 9142721 - 2¹⁰ = 9141697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9142723) 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, 653045 + ... + 653058.

It is an arithmetic number, because the mean of its divisors is an integer number (2612208).

Almost surely, 2^9142721 is an apocalyptic number.

It is an amenable number.

9142721 is a deficient number, since it is larger than the sum of its proper divisors (1306111).

9142721 is a wasteful number, since it uses less digits than its factorization.

9142721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1306110.

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

The square root of 9142721 is about 3023.6932714811. The cubic root of 9142721 is about 209.1021455324.

The spelling of 9142721 in words is "nine million, one hundred forty-two thousand, seven hundred twenty-one".