2581649 has 8 divisors (see below), whose sum is σ = 3045888. Its totient is φ = 2141280.

The previous prime is 2581643. The next prime is 2581651. The reversal of 2581649 is 9461852.

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 2581649 - 2⁴ = 2581633 is a prime.

It is a super-5 number, since 5×2581649⁵ (a number of 33 digits) contains 55555 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2581643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5732 + ... + 6165.

It is an arithmetic number, because the mean of its divisors is an integer number (380736).

2^2581649 is an apocalyptic number.

It is an amenable number.

2581649 is a deficient number, since it is larger than the sum of its proper divisors (464239).

2581649 is a wasteful number, since it uses less digits than its factorization.

2581649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11935.

The product of its digits is 17280, while the sum is 35.

The square root of 2581649 is about 1606.7510697056. The cubic root of 2581649 is about 137.1826111914.

The spelling of 2581649 in words is "two million, five hundred eighty-one thousand, six hundred forty-nine".