21768465309 has 8 divisors (see below), whose sum is σ = 29025402432. Its totient is φ = 14511919200.

The previous prime is 21768465239. The next prime is 21768465311. The reversal of 21768465309 is 90356486712.

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

It is not a de Polignac number, because 21768465309 - 2⁷ = 21768465181 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21768465349) 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, 76552 + ... + 222254.

It is an arithmetic number, because the mean of its divisors is an integer number (3628175304).

It is a 1-persistent number, because it is pandigital, but 2⋅21768465309 = 43536930618 is not.

Almost surely, 2^21768465309 is an apocalyptic number.

It is an amenable number.

21768465309 is a deficient number, since it is larger than the sum of its proper divisors (7256937123).

21768465309 is a wasteful number, since it uses less digits than its factorization.

21768465309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195507.

The product of its (nonzero) digits is 2177280, while the sum is 51.

The spelling of 21768465309 in words is "twenty-one billion, seven hundred sixty-eight million, four hundred sixty-five thousand, three hundred nine".