21730409165 has 8 divisors (see below), whose sum is σ = 26077282560. Its totient is φ = 17383799632.

The previous prime is 21730409153. The next prime is 21730409201. The reversal of 21730409165 is 56190403712.

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

It is a cyclic number.

It is not a de Polignac number, because 21730409165 - 2⁴ = 21730409149 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 284492 + ... + 352698.

It is an arithmetic number, because the mean of its divisors is an integer number (3259660320).

Almost surely, 2^21730409165 is an apocalyptic number.

It is an amenable number.

21730409165 is a deficient number, since it is larger than the sum of its proper divisors (4346873395).

21730409165 is an equidigital number, since it uses as much as digits as its factorization.

21730409165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131931.

The product of its (nonzero) digits is 45360, while the sum is 38.

The spelling of 21730409165 in words is "twenty-one billion, seven hundred thirty million, four hundred nine thousand, one hundred sixty-five".