20981321527 has 2 divisors, whose sum is σ = 20981321528. Its totient is φ = 20981321526.

The previous prime is 20981321497. The next prime is 20981321567. The reversal of 20981321527 is 72512318902.

It is an a-pointer prime, because the next prime (20981321567) can be obtained adding 20981321527 to its sum of digits (40).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20981321527 - 2²⁷ = 20847103799 is a prime.

It is a super-2 number, since 2×20981321527² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20981321527.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20981321567) 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, 10490660763 + 10490660764.

It is an arithmetic number, because the mean of its divisors is an integer number (10490660764).

Almost surely, 2^20981321527 is an apocalyptic number.

20981321527 is a deficient number, since it is larger than the sum of its proper divisors (1).

20981321527 is an equidigital number, since it uses as much as digits as its factorization.

20981321527 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60480, while the sum is 40.

The spelling of 20981321527 in words is "twenty billion, nine hundred eighty-one million, three hundred twenty-one thousand, five hundred twenty-seven".