21786598066 has 16 divisors (see below), whose sum is σ = 34305857280. Its totient is φ = 10363224240.

The previous prime is 21786598063. The next prime is 21786598069. The reversal of 21786598066 is 66089568712.

It is an interprime number because it is at equal distance from previous prime (21786598063) and next prime (21786598069).

It is a self number, because there is not a number n which added to its sum of digits gives 21786598066.

It is not an unprimeable number, because it can be changed into a prime (21786598063) 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, 2974281 + ... + 2981596.

It is an arithmetic number, because the mean of its divisors is an integer number (2144116080).

Almost surely, 2^21786598066 is an apocalyptic number.

21786598066 is a deficient number, since it is larger than the sum of its proper divisors (12519259214).

21786598066 is a wasteful number, since it uses less digits than its factorization.

21786598066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5955969.

The product of its (nonzero) digits is 8709120, while the sum is 58.

The spelling of 21786598066 in words is "twenty-one billion, seven hundred eighty-six million, five hundred ninety-eight thousand, sixty-six".