20641864589 has 2 divisors, whose sum is σ = 20641864590. Its totient is φ = 20641864588.

The previous prime is 20641864571. The next prime is 20641864679. The reversal of 20641864589 is 98546814602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15175776100 + 5466088489 = 123190^2 + 73933^2 .

It is a cyclic number.

It is not a de Polignac number, because 20641864589 - 2¹² = 20641860493 is a prime.

It is a super-2 number, since 2×20641864589² (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 20641864589.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20641864489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10320932294 + 10320932295.

It is an arithmetic number, because the mean of its divisors is an integer number (10320932295).

Almost surely, 2^20641864589 is an apocalyptic number.

It is an amenable number.

20641864589 is a deficient number, since it is larger than the sum of its proper divisors (1).

20641864589 is an equidigital number, since it uses as much as digits as its factorization.

20641864589 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3317760, while the sum is 53.

The spelling of 20641864589 in words is "twenty billion, six hundred forty-one million, eight hundred sixty-four thousand, five hundred eighty-nine".