550121721 has 4 divisors (see below), whose sum is σ = 733495632. Its totient is φ = 366747812.

The previous prime is 550121713. The next prime is 550121731. The reversal of 550121721 is 127121055.

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 550121721 - 2³ = 550121713 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 550121691 and 550121700.

It is not an unprimeable number, because it can be changed into a prime (550121701) 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, 91686951 + ... + 91686956.

It is an arithmetic number, because the mean of its divisors is an integer number (183373908).

Almost surely, 2^550121721 is an apocalyptic number.

It is an amenable number.

550121721 is a deficient number, since it is larger than the sum of its proper divisors (183373911).

550121721 is a wasteful number, since it uses less digits than its factorization.

550121721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183373910.

The product of its (nonzero) digits is 700, while the sum is 24.

The square root of 550121721 is about 23454.6737559916. The cubic root of 550121721 is about 819.3817077208.

Adding to 550121721 its reverse (127121055), we get a palindrome (677242776).

The spelling of 550121721 in words is "five hundred fifty million, one hundred twenty-one thousand, seven hundred twenty-one".