7521645 has 24 divisors (see below), whose sum is σ = 12350304. Its totient is φ = 3908896.

The previous prime is 7521641. The next prime is 7521649. The reversal of 7521645 is 5461257.

It is an interprime number because it is at equal distance from previous prime (7521641) and next prime (7521649).

It is not a de Polignac number, because 7521645 - 2² = 7521641 is a prime.

It is a super-3 number, since 3×7521645³ (a number of 22 digits) contains 333 as substring.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7521641) 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 23 ways as a sum of consecutive naturals, for example, 33022 + ... + 33248.

It is an arithmetic number, because the mean of its divisors is an integer number (514596).

Almost surely, 2^7521645 is an apocalyptic number.

It is an amenable number.

7521645 is a deficient number, since it is larger than the sum of its proper divisors (4828659).

7521645 is a wasteful number, since it uses less digits than its factorization.

7521645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 329 (or 282 counting only the distinct ones).

The product of its digits is 8400, while the sum is 30.

The square root of 7521645 is about 2742.5617586483. The cubic root of 7521645 is about 195.9315063323.

The spelling of 7521645 in words is "seven million, five hundred twenty-one thousand, six hundred forty-five".