20442326156561 has 4 divisors (see below), whose sum is σ = 20443010356800. Its totient is φ = 20441641956324.

The previous prime is 20442326156533. The next prime is 20442326156627. The reversal of 20442326156561 is 16565162324402.

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 20442326156561 - 2³⁸ = 20167448249617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20442326186561) 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, 342055301 + ... + 342115058.

It is an arithmetic number, because the mean of its divisors is an integer number (5110752589200).

Almost surely, 2^{20442326156561} is an apocalyptic number.

It is an amenable number.

20442326156561 is a deficient number, since it is larger than the sum of its proper divisors (684200239).

20442326156561 is an equidigital number, since it uses as much as digits as its factorization.

20442326156561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 684200238.

The product of its (nonzero) digits is 2073600, while the sum is 47.

The spelling of 20442326156561 in words is "twenty trillion, four hundred forty-two billion, three hundred twenty-six million, one hundred fifty-six thousand, five hundred sixty-one".