20506501706666 has 8 divisors (see below), whose sum is σ = 30759800016960. Its totient is φ = 10253235034348.

The previous prime is 20506501706657. The next prime is 20506501706687. The reversal of 20506501706666 is 66660710560502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×20506501706666² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6216626 + ... + 8925213.

It is an arithmetic number, because the mean of its divisors is an integer number (3844975002120).

Almost surely, 2^{20506501706666} is an apocalyptic number.

20506501706666 is a deficient number, since it is larger than the sum of its proper divisors (10253298310294).

20506501706666 is a wasteful number, since it uses less digits than its factorization.

20506501706666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15818988.

The product of its (nonzero) digits is 2721600, while the sum is 50.

The spelling of 20506501706666 in words is "twenty trillion, five hundred six billion, five hundred one million, seven hundred six thousand, six hundred sixty-six".