20680281621 has 12 divisors (see below), whose sum is σ = 29873038572. Its totient is φ = 13786152576.

The previous prime is 20680281581. The next prime is 20680281631. The reversal of 20680281621 is 12618208602.

20680281621 is a `hidden beast` number, since 2 + 0 + 6 + 8 + 0 + 28 + 1 + 621 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 4982948100 + 15697333521 = 70590^2 + 125289^2 .

It is not a de Polignac number, because 20680281621 - 2¹⁰ = 20680280597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20680281631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 178795 + ... + 270791.

It is an arithmetic number, because the mean of its divisors is an integer number (2489419881).

Almost surely, 2^20680281621 is an apocalyptic number.

It is an amenable number.

20680281621 is a deficient number, since it is larger than the sum of its proper divisors (9192756951).

20680281621 is a wasteful number, since it uses less digits than its factorization.

20680281621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116980 (or 116977 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The spelling of 20680281621 in words is "twenty billion, six hundred eighty million, two hundred eighty-one thousand, six hundred twenty-one".