553661 has 4 divisors (see below), whose sum is σ = 555324. Its totient is φ = 552000.

The previous prime is 553649. The next prime is 553667. The reversal of 553661 is 166355.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 55225 + 498436 = 235^2 + 706^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-553661 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 553661.

It is a congruent number.

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

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 140 + ... + 1061.

It is an arithmetic number, because the mean of its divisors is an integer number (138831).

2⁵⁵³⁶⁶¹ is an apocalyptic number.

It is an amenable number.

553661 is a deficient number, since it is larger than the sum of its proper divisors (1663).

553661 is a wasteful number, since it uses less digits than its factorization.

553661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1662.

The product of its digits is 2700, while the sum is 26.

The square root of 553661 is about 744.0840006343. The cubic root of 553661 is about 82.1135152020.

The spelling of 553661 in words is "five hundred fifty-three thousand, six hundred sixty-one".