20445664667 has 4 divisors (see below), whose sum is σ = 20453287800. Its totient is φ = 20438041536.

The previous prime is 20445664663. The next prime is 20445664693. The reversal of 20445664667 is 76646654402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 76646654402 = 2 ⋅38323327201.

It is a cyclic number.

It is not a de Polignac number, because 20445664667 - 2² = 20445664663 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20445664661) 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, 3807542 + ... + 3812907.

It is an arithmetic number, because the mean of its divisors is an integer number (5113321950).

Almost surely, 2^20445664667 is an apocalyptic number.

20445664667 is a deficient number, since it is larger than the sum of its proper divisors (7623133).

20445664667 is an equidigital number, since it uses as much as digits as its factorization.

20445664667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7623132.

The product of its (nonzero) digits is 5806080, while the sum is 50.

The spelling of 20445664667 in words is "twenty billion, four hundred forty-five million, six hundred sixty-four thousand, six hundred sixty-seven".