21789241309 has 32 divisors (see below), whose sum is σ = 25441485696. Its totient is φ = 18441861120.

The previous prime is 21789241303. The next prime is 21789241403. The reversal of 21789241309 is 90314298712.

It is a happy number.

It is not a de Polignac number, because 21789241309 - 2⁹ = 21789240797 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21789241303) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8119882 + ... + 8122564.

It is an arithmetic number, because the mean of its divisors is an integer number (795046428).

Almost surely, 2^21789241309 is an apocalyptic number.

It is an amenable number.

21789241309 is a deficient number, since it is larger than the sum of its proper divisors (3652244387).

21789241309 is a wasteful number, since it uses less digits than its factorization.

21789241309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3165.

The product of its (nonzero) digits is 217728, while the sum is 46.

The spelling of 21789241309 in words is "twenty-one billion, seven hundred eighty-nine million, two hundred forty-one thousand, three hundred nine".