561727021 has 4 divisors (see below), whose sum is σ = 564974172. Its totient is φ = 558479872.

The previous prime is 561726961. The next prime is 561727027. The reversal of 561727021 is 120727165.

561727021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 331749796 + 229977225 = 18214^2 + 15165^2 .

It is a cyclic number.

It is not a de Polignac number, because 561727021 - 2¹¹ = 561724973 is a prime.

It is a super-2 number, since 2×561727021² = 631074492243068882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561727027) 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, 1623316 + ... + 1623661.

It is an arithmetic number, because the mean of its divisors is an integer number (141243543).

Almost surely, 2^561727021 is an apocalyptic number.

It is an amenable number.

561727021 is a deficient number, since it is larger than the sum of its proper divisors (3247151).

561727021 is a wasteful number, since it uses less digits than its factorization.

561727021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3247150.

The product of its (nonzero) digits is 5880, while the sum is 31.

The square root of 561727021 is about 23700.7810208862. The cubic root of 561727021 is about 825.1035173442.

The spelling of 561727021 in words is "five hundred sixty-one million, seven hundred twenty-seven thousand, twenty-one".