20015667165661 has 4 divisors (see below), whose sum is σ = 20885913564192. Its totient is φ = 19145420767132.

The previous prime is 20015667165649. The next prime is 20015667165671. The reversal of 20015667165661 is 16656176651002.

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 20015667165661 - 2⁵ = 20015667165629 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20015667165599 and 20015667165608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20015667165601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 435123199231 + ... + 435123199276.

It is an arithmetic number, because the mean of its divisors is an integer number (5221478391048).

Almost surely, 2^{20015667165661} is an apocalyptic number.

It is an amenable number.

20015667165661 is a deficient number, since it is larger than the sum of its proper divisors (870246398531).

20015667165661 is an equidigital number, since it uses as much as digits as its factorization.

20015667165661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 870246398530.

The product of its (nonzero) digits is 2721600, while the sum is 52.

The spelling of 20015667165661 in words is "twenty trillion, fifteen billion, six hundred sixty-seven million, one hundred sixty-five thousand, six hundred sixty-one".