6451581 has 4 divisors (see below), whose sum is σ = 8602112. Its totient is φ = 4301052.

The previous prime is 6451573. The next prime is 6451609. The reversal of 6451581 is 1851546.

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 not a de Polignac number, because 6451581 - 2³ = 6451573 is a prime.

It is a super-2 number, since 2×6451581² = 83245794799122, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6451541) 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, 1075261 + ... + 1075266.

It is an arithmetic number, because the mean of its divisors is an integer number (2150528).

Almost surely, 2^6451581 is an apocalyptic number.

It is an amenable number.

6451581 is a deficient number, since it is larger than the sum of its proper divisors (2150531).

6451581 is a wasteful number, since it uses less digits than its factorization.

6451581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2150530.

The product of its digits is 4800, while the sum is 30.

The square root of 6451581 is about 2539.9962598398. The cubic root of 6451581 is about 186.1610063857.

The spelling of 6451581 in words is "six million, four hundred fifty-one thousand, five hundred eighty-one".