20156610666 has 8 divisors (see below), whose sum is σ = 40313221344. Its totient is φ = 6718870220.

The previous prime is 20156610601. The next prime is 20156610697. The reversal of 20156610666 is 66601665102.

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

20156610666 is an admirable number.

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, 1679717550 + ... + 1679717561.

It is an arithmetic number, because the mean of its divisors is an integer number (5039152668).

Almost surely, 2^20156610666 is an apocalyptic number.

20156610666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20156610666 is a wasteful number, since it uses less digits than its factorization.

20156610666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3359435116.

The product of its (nonzero) digits is 77760, while the sum is 39.

The spelling of 20156610666 in words is "twenty billion, one hundred fifty-six million, six hundred ten thousand, six hundred sixty-six".