561573361001621 has 4 divisors (see below), whose sum is σ = 585989594088672. Its totient is φ = 537157127914572.

The previous prime is 561573361001603. The next prime is 561573361001651. The reversal of 561573361001621 is 126100163375165.

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 561573361001621 - 2³⁴ = 561556181132437 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 (561573361001651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12208116543491 + ... + 12208116543536.

It is an arithmetic number, because the mean of its divisors is an integer number (146497398522168).

Almost surely, 2^{561573361001621} is an apocalyptic number.

It is an amenable number.

561573361001621 is a deficient number, since it is larger than the sum of its proper divisors (24416233087051).

561573361001621 is a wasteful number, since it uses less digits than its factorization.

561573361001621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24416233087050.

The product of its (nonzero) digits is 680400, while the sum is 47.

The spelling of 561573361001621 in words is "five hundred sixty-one trillion, five hundred seventy-three billion, three hundred sixty-one million, one thousand, six hundred twenty-one".