1625581 has 2 divisors, whose sum is σ = 1625582. Its totient is φ = 1625580.

The previous prime is 1625573. The next prime is 1625587. The reversal of 1625581 is 1855261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1121481 + 504100 = 1059^2 + 710^2 .

It is a cyclic number.

It is not a de Polignac number, because 1625581 - 2³ = 1625573 is a prime.

It is a super-2 number, since 2×1625581² = 5285027175122, which contains 22 as substring.

1625581 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1625587) 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 as a sum of consecutive naturals, namely, 812790 + 812791.

It is an arithmetic number, because the mean of its divisors is an integer number (812791).

2^1625581 is an apocalyptic number.

It is an amenable number.

1625581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1625581 is an equidigital number, since it uses as much as digits as its factorization.

1625581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2400, while the sum is 28.

The square root of 1625581 is about 1274.9827449813. The cubic root of 1625581 is about 117.5807442596.

The spelling of 1625581 in words is "one million, six hundred twenty-five thousand, five hundred eighty-one".