289999999981 has 4 divisors (see below), whose sum is σ = 290005192192. Its totient is φ = 289994807772.

The previous prime is 289999999921. The next prime is 289999999987. The reversal of 289999999981 is 189999999982.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 289999999981 - 2¹⁷ = 289999868909 is a prime.

It is a super-2 number, since 2×289999999981² (a number of 24 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 (289999999987) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2511405 + ... + 2624338.

It is an arithmetic number, because the mean of its divisors is an integer number (72501298048).

Almost surely, 2^289999999981 is an apocalyptic number.

It is an amenable number.

289999999981 is a deficient number, since it is larger than the sum of its proper divisors (5192211).

289999999981 is an equidigital number, since it uses as much as digits as its factorization.

289999999981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5192210.

The product of its digits is 5509980288, while the sum is 91.

Subtracting from 289999999981 its reverse (189999999982), we obtain a palindrome (99999999999).

The spelling of 289999999981 in words is "two hundred eighty-nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred eighty-one".