20999761564706 has 8 divisors (see below), whose sum is σ = 31499826657984. Its totient is φ = 10499819345380.

The previous prime is 20999761564681. The next prime is 20999761564723. The reversal of 20999761564706 is 60746516799902.

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

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20999761564706.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30290030 + ... + 30975561.

It is an arithmetic number, because the mean of its divisors is an integer number (3937478332248).

Almost surely, 2^{20999761564706} is an apocalyptic number.

20999761564706 is a deficient number, since it is larger than the sum of its proper divisors (10500065093278).

20999761564706 is a wasteful number, since it uses less digits than its factorization.

20999761564706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61436976.

The product of its (nonzero) digits is 308629440, while the sum is 71.

The spelling of 20999761564706 in words is "twenty trillion, nine hundred ninety-nine billion, seven hundred sixty-one million, five hundred sixty-four thousand, seven hundred six".