20705656211672 has 8 divisors (see below), whose sum is σ = 38823105396900. Its totient is φ = 10352828105832.

The previous prime is 20705656211663. The next prime is 20705656211677. The reversal of 20705656211672 is 27611265650702.

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 20705656211672.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20705656211677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1294103513222 + ... + 1294103513237.

Almost surely, 2^{20705656211672} is an apocalyptic number.

It is an amenable number.

20705656211672 is a deficient number, since it is larger than the sum of its proper divisors (18117449185228).

20705656211672 is a wasteful number, since it uses less digits than its factorization.

20705656211672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2588207026465 (or 2588207026461 counting only the distinct ones).

The product of its (nonzero) digits is 2116800, while the sum is 50.

The spelling of 20705656211672 in words is "twenty trillion, seven hundred five billion, six hundred fifty-six million, two hundred eleven thousand, six hundred seventy-two".