20981327473 has 2 divisors, whose sum is σ = 20981327474. Its totient is φ = 20981327472.

The previous prime is 20981327449. The next prime is 20981327509. The reversal of 20981327473 is 37472318902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20844718129 + 136609344 = 144377^2 + 11688^2 .

It is a cyclic number.

It is not a de Polignac number, because 20981327473 - 2⁵ = 20981327441 is a prime.

It is a super-2 number, since 2×20981327473² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20981327443) by changing a digit.

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 as a sum of consecutive naturals, namely, 10490663736 + 10490663737.

It is an arithmetic number, because the mean of its divisors is an integer number (10490663737).

Almost surely, 2^20981327473 is an apocalyptic number.

It is an amenable number.

20981327473 is a deficient number, since it is larger than the sum of its proper divisors (1).

20981327473 is an equidigital number, since it uses as much as digits as its factorization.

20981327473 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 508032, while the sum is 46.

The spelling of 20981327473 in words is "twenty billion, nine hundred eighty-one million, three hundred twenty-seven thousand, four hundred seventy-three".