20705650816 has 16 divisors (see below), whose sum is σ = 41249538990. Its totient is φ = 10352825344.

The previous prime is 20705650787. The next prime is 20705650829. The reversal of 20705650816 is 61805650702.

It can be written as a sum of positive squares in only one way, i.e., 16665777216 + 4039873600 = 129096^2 + 63560^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80881321 + ... + 80881576.

Almost surely, 2^20705650816 is an apocalyptic number.

It is an amenable number.

20705650816 is a deficient number, since it is larger than the sum of its proper divisors (20543888174).

20705650816 is an equidigital number, since it uses as much as digits as its factorization.

20705650816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161762911 (or 161762899 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 40.

The spelling of 20705650816 in words is "twenty billion, seven hundred five million, six hundred fifty thousand, eight hundred sixteen".