1366561 has 9 divisors (see below), whose sum is σ = 1599249. Its totient is φ = 1164324.

The previous prime is 1366549. The next prime is 1366577. The reversal of 1366561 is 1656631.

1366561 = T₃₅ + T₃₆ + ... + T₂₀₁.

The square root of 1366561 is 1169.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 1366561 - 2⁵ = 1366529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1366531) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 8100 + ... + 8266.

2^1366561 is an apocalyptic number.

1366561 is the 1169-th square number.

1366561 is the 585-th centered octagonal number.

It is an amenable number.

1366561 is a deficient number, since it is larger than the sum of its proper divisors (232688).

1366561 is an frugal number, since it uses more digits than its factorization.

1366561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 348 (or 174 counting only the distinct ones).

The product of its digits is 3240, while the sum is 28.

The cubic root of 1366561 is about 110.9710445806.

The spelling of 1366561 in words is "one million, three hundred sixty-six thousand, five hundred sixty-one".