20466180561 has 4 divisors (see below), whose sum is σ = 27288240752. Its totient is φ = 13644120372.

The previous prime is 20466180557. The next prime is 20466180569. The reversal of 20466180561 is 16508166402.

It is a happy number.

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 not a de Polignac number, because 20466180561 - 2² = 20466180557 is a prime.

It is a super-3 number, since 3×20466180561³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20466180569) 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, 3411030091 + ... + 3411030096.

It is an arithmetic number, because the mean of its divisors is an integer number (6822060188).

Almost surely, 2^20466180561 is an apocalyptic number.

It is an amenable number.

20466180561 is a deficient number, since it is larger than the sum of its proper divisors (6822060191).

20466180561 is an equidigital number, since it uses as much as digits as its factorization.

20466180561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6822060190.

The product of its (nonzero) digits is 69120, while the sum is 39.

The spelling of 20466180561 in words is "twenty billion, four hundred sixty-six million, one hundred eighty thousand, five hundred sixty-one".