7421581 has 8 divisors (see below), whose sum is σ = 7553304. Its totient is φ = 7291200.

The previous prime is 7421569. The next prime is 7421587. The reversal of 7421581 is 1851247.

It can be written as a sum of positive squares in 4 ways, for example, as 5447556 + 1974025 = 2334^2 + 1405^2 .

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 7421581 - 2¹⁵ = 7388813 is a prime.

It is a super-2 number, since 2×7421581² = 110159729079122, 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 (7421587) 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 7 ways as a sum of consecutive naturals, for example, 19711 + ... + 20083.

It is an arithmetic number, because the mean of its divisors is an integer number (944163).

Almost surely, 2^7421581 is an apocalyptic number.

It is an amenable number.

7421581 is a deficient number, since it is larger than the sum of its proper divisors (131723).

7421581 is a wasteful number, since it uses less digits than its factorization.

7421581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 671.

The product of its digits is 2240, while the sum is 28.

The square root of 7421581 is about 2724.2578805979. The cubic root of 7421581 is about 195.0587681734.

The spelling of 7421581 in words is "seven million, four hundred twenty-one thousand, five hundred eighty-one".