561773621 has 4 divisors (see below), whose sum is σ = 562664544. Its totient is φ = 560882700.

The previous prime is 561773609. The next prime is 561773623. The reversal of 561773621 is 126377165.

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 561773621 - 2¹⁴ = 561757237 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 (561773623) 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, 444515 + ... + 445776.

It is an arithmetic number, because the mean of its divisors is an integer number (140666136).

Almost surely, 2^561773621 is an apocalyptic number.

It is an amenable number.

561773621 is a deficient number, since it is larger than the sum of its proper divisors (890923).

561773621 is an equidigital number, since it uses as much as digits as its factorization.

561773621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 890922.

The product of its digits is 52920, while the sum is 38.

The square root of 561773621 is about 23701.7640904638. The cubic root of 561773621 is about 825.1263331481.

The spelling of 561773621 in words is "five hundred sixty-one million, seven hundred seventy-three thousand, six hundred twenty-one".