1624561 has 4 divisors (see below), whose sum is σ = 1627812. Its totient is φ = 1621312.

The previous prime is 1624529. The next prime is 1624573. The reversal of 1624561 is 1654261.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1654261 = 7 ⋅236323.

It can be written as a sum of positive squares in 2 ways, for example, as 136161 + 1488400 = 369^2 + 1220^2 .

It is a cyclic number.

It is not a de Polignac number, because 1624561 - 2⁵ = 1624529 is a prime.

It is a Duffinian number.

1624561 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1624501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 700 + ... + 1933.

It is an arithmetic number, because the mean of its divisors is an integer number (406953).

2^1624561 is an apocalyptic number.

It is an amenable number.

1624561 is a deficient number, since it is larger than the sum of its proper divisors (3251).

1624561 is an equidigital number, since it uses as much as digits as its factorization.

1624561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3250.

The product of its digits is 1440, while the sum is 25.

The square root of 1624561 is about 1274.5826768005. The cubic root of 1624561 is about 117.5561463974.

The spelling of 1624561 in words is "one million, six hundred twenty-four thousand, five hundred sixty-one".