1266553 has 4 divisors (see below), whose sum is σ = 1288080. Its totient is φ = 1245028.

The previous prime is 1266539. The next prime is 1266557. The reversal of 1266553 is 3556621.

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, and also an emirpimes, since its reverse is a distinct semiprime: 3556621 = 17 ⋅209213.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1266553 is a prime.

It is a Duffinian number.

1266553 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1266557) 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, 10675 + ... + 10792.

It is an arithmetic number, because the mean of its divisors is an integer number (322020).

2^1266553 is an apocalyptic number.

It is an amenable number.

1266553 is a deficient number, since it is larger than the sum of its proper divisors (21527).

1266553 is an equidigital number, since it uses as much as digits as its factorization.

1266553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21526.

The product of its digits is 5400, while the sum is 28.

The square root of 1266553 is about 1125.4123688675. The cubic root of 1266553 is about 108.1951489950.

The spelling of 1266553 in words is "one million, two hundred sixty-six thousand, five hundred fifty-three".