7491521 has 4 divisors (see below), whose sum is σ = 7507392. Its totient is φ = 7475652.

The previous prime is 7491493. The next prime is 7491551. The reversal of 7491521 is 1251947.

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 not a de Polignac number, because 7491521 - 2⁶ = 7491457 is a prime.

It is a super-2 number, since 2×7491521² = 112245773786882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7491551) 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, 7205 + ... + 8178.

It is an arithmetic number, because the mean of its divisors is an integer number (1876848).

Almost surely, 2^7491521 is an apocalyptic number.

It is an amenable number.

7491521 is a deficient number, since it is larger than the sum of its proper divisors (15871).

7491521 is a wasteful number, since it uses less digits than its factorization.

7491521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15870.

The product of its digits is 2520, while the sum is 29.

The square root of 7491521 is about 2737.0643032271. The cubic root of 7491521 is about 195.6695894370.

The spelling of 7491521 in words is "seven million, four hundred ninety-one thousand, five hundred twenty-one".