550720661 has 4 divisors (see below), whose sum is σ = 583116012. Its totient is φ = 518325312.

The previous prime is 550720649. The next prime is 550720669. The reversal of 550720661 is 166027055.

It is a happy number.

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 175562500 + 375158161 = 13250^2 + 19369^2 .

It is a cyclic number.

It is not a de Polignac number, because 550720661 - 2²⁶ = 483611797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (550720669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16197650 + ... + 16197683.

It is an arithmetic number, because the mean of its divisors is an integer number (145779003).

Almost surely, 2^550720661 is an apocalyptic number.

It is an amenable number.

550720661 is a deficient number, since it is larger than the sum of its proper divisors (32395351).

550720661 is a wasteful number, since it uses less digits than its factorization.

550720661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32395350.

The product of its (nonzero) digits is 12600, while the sum is 32.

The square root of 550720661 is about 23467.4383135442. The cubic root of 550720661 is about 819.6789646522.

The spelling of 550720661 in words is "five hundred fifty million, seven hundred twenty thousand, six hundred sixty-one".