8730921 has 4 divisors (see below), whose sum is σ = 11641232. Its totient is φ = 5820612.

The previous prime is 8730919. The next prime is 8730929. The reversal of 8730921 is 1290378.

It is a happy number.

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 not a de Polignac number, because 8730921 - 2¹ = 8730919 is a prime.

It is a Duffinian number.

8730921 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (8730929) 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, 1455151 + ... + 1455156.

It is an arithmetic number, because the mean of its divisors is an integer number (2910308).

Almost surely, 2^8730921 is an apocalyptic number.

It is an amenable number.

8730921 is a deficient number, since it is larger than the sum of its proper divisors (2910311).

8730921 is a wasteful number, since it uses less digits than its factorization.

8730921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2910310.

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 8730921 is about 2954.8131920648. The cubic root of 8730921 is about 205.9143845688.

The spelling of 8730921 in words is "eight million, seven hundred thirty thousand, nine hundred twenty-one".