9021721 has 4 divisors (see below), whose sum is σ = 9136000. Its totient is φ = 8907444.

The previous prime is 9021709. The next prime is 9021731. The reversal of 9021721 is 1271209.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9021721 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 9021692 and 9021701.

It is not an unprimeable number, because it can be changed into a prime (9021731) 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, 57021 + ... + 57178.

It is an arithmetic number, because the mean of its divisors is an integer number (2284000).

Almost surely, 2^9021721 is an apocalyptic number.

It is an amenable number.

9021721 is a deficient number, since it is larger than the sum of its proper divisors (114279).

9021721 is a wasteful number, since it uses less digits than its factorization.

9021721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114278.

The product of its (nonzero) digits is 252, while the sum is 22.

The square root of 9021721 is about 3003.6179850307. The cubic root of 9021721 is about 208.1755867559.

The spelling of 9021721 in words is "nine million, twenty-one thousand, seven hundred twenty-one".