20682727921 has 2 divisors, whose sum is σ = 20682727922. Its totient is φ = 20682727920.

The previous prime is 20682727907. The next prime is 20682728063. The reversal of 20682727921 is 12972728602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17429280400 + 3253447521 = 132020^2 + 57039^2 .

It is a cyclic number.

It is not a de Polignac number, because 20682727921 - 2¹⁷ = 20682596849 is a prime.

It is a super-2 number, since 2×20682727921² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20682727721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10341363960 + 10341363961.

It is an arithmetic number, because the mean of its divisors is an integer number (10341363961).

Almost surely, 2^20682727921 is an apocalyptic number.

It is an amenable number.

20682727921 is a deficient number, since it is larger than the sum of its proper divisors (1).

20682727921 is an equidigital number, since it uses as much as digits as its factorization.

20682727921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 338688, while the sum is 46.

The spelling of 20682727921 in words is "twenty billion, six hundred eighty-two million, seven hundred twenty-seven thousand, nine hundred twenty-one".