20931181589 has 2 divisors, whose sum is σ = 20931181590. Its totient is φ = 20931181588.

The previous prime is 20931181559. The next prime is 20931181637. The reversal of 20931181589 is 98518113902.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19773140689 + 1158040900 = 140617^2 + 34030^2 .

It is a cyclic number.

It is not a de Polignac number, because 20931181589 - 2⁸ = 20931181333 is a prime.

It is a super-2 number, since 2×20931181589² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20931181519) 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, 10465590794 + 10465590795.

It is an arithmetic number, because the mean of its divisors is an integer number (10465590795).

Almost surely, 2^20931181589 is an apocalyptic number.

It is an amenable number.

20931181589 is a deficient number, since it is larger than the sum of its proper divisors (1).

20931181589 is an equidigital number, since it uses as much as digits as its factorization.

20931181589 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 155520, while the sum is 47.

The spelling of 20931181589 in words is "twenty billion, nine hundred thirty-one million, one hundred eighty-one thousand, five hundred eighty-nine".