7421509 has 2 divisors, whose sum is σ = 7421510. Its totient is φ = 7421508.

The previous prime is 7421489. The next prime is 7421539. The reversal of 7421509 is 9051247.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4708900 + 2712609 = 2170^2 + 1647^2 .

It is a cyclic number.

It is not a de Polignac number, because 7421509 - 2¹⁵ = 7388741 is a prime.

It is a super-3 number, since 3×7421509³ (a number of 22 digits) contains 333 as substring.

It is a Chen prime.

7421509 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7421539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3710754 + 3710755.

It is an arithmetic number, because the mean of its divisors is an integer number (3710755).

Almost surely, 2^7421509 is an apocalyptic number.

It is an amenable number.

7421509 is a deficient number, since it is larger than the sum of its proper divisors (1).

7421509 is an equidigital number, since it uses as much as digits as its factorization.

7421509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 7421509 is about 2724.2446659579. The cubic root of 7421509 is about 195.0581373879.

The spelling of 7421509 in words is "seven million, four hundred twenty-one thousand, five hundred nine".