21861066463 has 4 divisors (see below), whose sum is σ = 22394263248. Its totient is φ = 21327869680.

The previous prime is 21861066419. The next prime is 21861066467. The reversal of 21861066463 is 36466016812.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21861066463 - 2¹⁷ = 21860935391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21861066467) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266598331 + ... + 266598412.

It is an arithmetic number, because the mean of its divisors is an integer number (5598565812).

Almost surely, 2^21861066463 is an apocalyptic number.

21861066463 is a deficient number, since it is larger than the sum of its proper divisors (533196785).

21861066463 is an equidigital number, since it uses as much as digits as its factorization.

21861066463 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 533196784.

The product of its (nonzero) digits is 248832, while the sum is 43.

The spelling of 21861066463 in words is "twenty-one billion, eight hundred sixty-one million, sixty-six thousand, four hundred sixty-three".