555145721 has 4 divisors (see below), whose sum is σ = 597849252. Its totient is φ = 512442192.

The previous prime is 555145709. The next prime is 555145729. The reversal of 555145721 is 127541555.

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 276756496 + 278389225 = 16636^2 + 16685^2 .

It is a cyclic number.

It is not a de Polignac number, because 555145721 - 2¹⁰ = 555144697 is a prime.

It is not an unprimeable number, because it can be changed into a prime (555145729) 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, 21351746 + ... + 21351771.

It is an arithmetic number, because the mean of its divisors is an integer number (149462313).

Almost surely, 2^555145721 is an apocalyptic number.

It is an amenable number.

555145721 is a deficient number, since it is larger than the sum of its proper divisors (42703531).

555145721 is a wasteful number, since it uses less digits than its factorization.

555145721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42703530.

The product of its digits is 35000, while the sum is 35.

The square root of 555145721 is about 23561.5305317800. The cubic root of 555145721 is about 821.8684939289.

The spelling of 555145721 in words is "five hundred fifty-five million, one hundred forty-five thousand, seven hundred twenty-one".