20000081989 has 4 divisors (see below), whose sum is σ = 20071256940. Its totient is φ = 19928907040.

The previous prime is 20000081977. The next prime is 20000081999. The reversal of 20000081989 is 98918000002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 98918000002 = 2 ⋅49459000001.

It can be written as a sum of positive squares in 2 ways, for example, as 7667979489 + 12332102500 = 87567^2 + 111050^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20000081989 is a prime.

It is a super-2 number, since 2×20000081989² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20000081909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35587054 + ... + 35587615.

It is an arithmetic number, because the mean of its divisors is an integer number (5017814235).

Almost surely, 2^20000081989 is an apocalyptic number.

It is an amenable number.

20000081989 is a deficient number, since it is larger than the sum of its proper divisors (71174951).

20000081989 is an equidigital number, since it uses as much as digits as its factorization.

20000081989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71174950.

The product of its (nonzero) digits is 10368, while the sum is 37.

The spelling of 20000081989 in words is "twenty billion, eighty-one thousand, nine hundred eighty-nine".