20761606815666 has 32 divisors (see below), whose sum is σ = 41681874706560. Its totient is φ = 6894093076224.

The previous prime is 20761606815619. The next prime is 20761606815707. The reversal of 20761606815666 is 66651860616702.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 124466616 + ... + 124633308.

It is an arithmetic number, because the mean of its divisors is an integer number (1302558584580).

Almost surely, 2^{20761606815666} is an apocalyptic number.

20761606815666 is an abundant number, since it is smaller than the sum of its proper divisors (20920267890894).

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

20761606815666 is a wasteful number, since it uses less digits than its factorization.

20761606815666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245890.

The product of its (nonzero) digits is 26127360, while the sum is 60.

The spelling of 20761606815666 in words is "twenty trillion, seven hundred sixty-one billion, six hundred six million, eight hundred fifteen thousand, six hundred sixty-six".