553666 has 4 divisors (see below), whose sum is σ = 830502. Its totient is φ = 276832.

The previous prime is 553649. The next prime is 553667. The reversal of 553666 is 666355.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 666355 = 5 ⋅133271.

It can be written as a sum of positive squares in only one way, i.e., 416025 + 137641 = 645^2 + 371^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (553667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 138415 + ... + 138418.

2⁵⁵³⁶⁶⁶ is an apocalyptic number.

553666 is a deficient number, since it is larger than the sum of its proper divisors (276836).

553666 is a wasteful number, since it uses less digits than its factorization.

553666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276835.

The product of its digits is 16200, while the sum is 31.

The square root of 553666 is about 744.0873604625. The cubic root of 553666 is about 82.1137623847.

It can be divided in two parts, 55 and 3666, that added together give a square (3721 = 61²).

The spelling of 553666 in words is "five hundred fifty-three thousand, six hundred sixty-six".