7531921 has 4 divisors (see below), whose sum is σ = 7635172. Its totient is φ = 7428672.

The previous prime is 7531919. The next prime is 7531933. The reversal of 7531921 is 1291357.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3686400 + 3845521 = 1920^2 + 1961^2 .

It is a cyclic number.

It is not a de Polignac number, because 7531921 - 2¹ = 7531919 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7531921.

It is not an unprimeable number, because it can be changed into a prime (7531991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51516 + ... + 51661.

It is an arithmetic number, because the mean of its divisors is an integer number (1908793).

Almost surely, 2^7531921 is an apocalyptic number.

7531921 is the 1585-th hex number.

It is an amenable number.

7531921 is a deficient number, since it is larger than the sum of its proper divisors (103251).

7531921 is a wasteful number, since it uses less digits than its factorization.

7531921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103250.

The product of its digits is 1890, while the sum is 28.

The square root of 7531921 is about 2744.4345501396. The cubic root of 7531921 is about 196.0206923177.

The spelling of 7531921 in words is "seven million, five hundred thirty-one thousand, nine hundred twenty-one".