2581406 has 8 divisors (see below), whose sum is σ = 4005720. Its totient is φ = 1246168.

The previous prime is 2581393. The next prime is 2581409. The reversal of 2581406 is 6041852.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2581409) 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, 22196 + ... + 22311.

It is an arithmetic number, because the mean of its divisors is an integer number (500715).

2^2581406 is an apocalyptic number.

2581406 is a deficient number, since it is larger than the sum of its proper divisors (1424314).

2581406 is a wasteful number, since it uses less digits than its factorization.

2581406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44538.

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 2581406 is about 1606.6754494919. The cubic root of 2581406 is about 137.1783069114.

The spelling of 2581406 in words is "two million, five hundred eighty-one thousand, four hundred six".