7381921 has 8 divisors (see below), whose sum is σ = 7666920. Its totient is φ = 7099008.

The previous prime is 7381909. The next prime is 7381931. The reversal of 7381921 is 1291837.

It can be written as a sum of positive squares in 4 ways, for example, as 950625 + 6431296 = 975^2 + 2536^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 7381921 - 2⁵ = 7381889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7381931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12975 + ... + 13531.

It is an arithmetic number, because the mean of its divisors is an integer number (958365).

Almost surely, 2^7381921 is an apocalyptic number.

It is an amenable number.

7381921 is a deficient number, since it is larger than the sum of its proper divisors (284999).

7381921 is a wasteful number, since it uses less digits than its factorization.

7381921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1043.

The product of its digits is 3024, while the sum is 31.

The square root of 7381921 is about 2716.9690833721. The cubic root of 7381921 is about 194.7106908599.

The spelling of 7381921 in words is "seven million, three hundred eighty-one thousand, nine hundred twenty-one".