1840561 has 2 divisors, whose sum is σ = 1840562. Its totient is φ = 1840560.

The previous prime is 1840541. The next prime is 1840577. The reversal of 1840561 is 1650481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1806336 + 34225 = 1344^2 + 185^2 .

It is a cyclic number.

It is not a de Polignac number, because 1840561 - 2⁹ = 1840049 is a prime.

It is an Ulam number.

1840561 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1840541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 920280 + 920281.

It is an arithmetic number, because the mean of its divisors is an integer number (920281).

2^1840561 is an apocalyptic number.

It is an amenable number.

1840561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1840561 is an equidigital number, since it uses as much as digits as its factorization.

1840561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 1840561 is about 1356.6727682090. The cubic root of 1840561 is about 122.5509658815.

It can be divided in two parts, 1840 and 561, that added together give a 4-th power (2401 = 7⁴).

The spelling of 1840561 in words is "one million, eight hundred forty thousand, five hundred sixty-one".