1366621 has 4 divisors (see below), whose sum is σ = 1384000. Its totient is φ = 1349244.

The previous prime is 1366609. The next prime is 1366627. The reversal of 1366621 is 1266631.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1366621 - 2⁷ = 1366493 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1366627) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8571 + ... + 8728.

It is an arithmetic number, because the mean of its divisors is an integer number (346000).

2^1366621 is an apocalyptic number.

It is an amenable number.

1366621 is a deficient number, since it is larger than the sum of its proper divisors (17379).

1366621 is an equidigital number, since it uses as much as digits as its factorization.

1366621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17378.

The product of its digits is 1296, while the sum is 25.

The square root of 1366621 is about 1169.0256626781. The cubic root of 1366621 is about 110.9726686489.

The spelling of 1366621 in words is "one million, three hundred sixty-six thousand, six hundred twenty-one".