21598423489 has 4 divisors (see below), whose sum is σ = 22735182640. Its totient is φ = 20461664340.

The previous prime is 21598423487. The next prime is 21598423507. The reversal of 21598423489 is 98432489512.

It is a happy number.

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 21598423489 - 2¹ = 21598423487 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21598423481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 568379547 + ... + 568379584.

It is an arithmetic number, because the mean of its divisors is an integer number (5683795660).

Almost surely, 2^21598423489 is an apocalyptic number.

It is an amenable number.

21598423489 is a deficient number, since it is larger than the sum of its proper divisors (1136759151).

21598423489 is a wasteful number, since it uses less digits than its factorization.

21598423489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1136759150.

The product of its digits is 4976640, while the sum is 55.

The spelling of 21598423489 in words is "twenty-one billion, five hundred ninety-eight million, four hundred twenty-three thousand, four hundred eighty-nine".