21138845289 has 8 divisors (see below), whose sum is σ = 28524707232. Its totient is φ = 13922773440.

The previous prime is 21138845263. The next prime is 21138845309. The reversal of 21138845289 is 98254883112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21138845289 - 2⁸ = 21138845033 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21138845209) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42447232 + ... + 42447729.

It is an arithmetic number, because the mean of its divisors is an integer number (3565588404).

Almost surely, 2^21138845289 is an apocalyptic number.

It is an amenable number.

21138845289 is a deficient number, since it is larger than the sum of its proper divisors (7385861943).

21138845289 is an equidigital number, since it uses as much as digits as its factorization.

21138845289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84895047.

The product of its digits is 1105920, while the sum is 51.

The spelling of 21138845289 in words is "twenty-one billion, one hundred thirty-eight million, eight hundred forty-five thousand, two hundred eighty-nine".