21765565382 has 8 divisors (see below), whose sum is σ = 35616379752. Its totient is φ = 9893438800.

The previous prime is 21765565363. The next prime is 21765565391. The reversal of 21765565382 is 28356556712.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21765565382.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 494671919 + ... + 494671962.

It is an arithmetic number, because the mean of its divisors is an integer number (4452047469).

Almost surely, 2^21765565382 is an apocalyptic number.

21765565382 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21765565382 is a deficient number, since it is larger than the sum of its proper divisors (13850814370).

21765565382 is a wasteful number, since it uses less digits than its factorization.

21765565382 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 989343894.

The product of its digits is 3024000, while the sum is 50.

The spelling of 21765565382 in words is "twenty-one billion, seven hundred sixty-five million, five hundred sixty-five thousand, three hundred eighty-two".