21259166716 has 12 divisors (see below), whose sum is σ = 37229955840. Its totient is φ = 10622036480.

The previous prime is 21259166713. The next prime is 21259166717. The reversal of 21259166716 is 61766195212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21259166711) 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, 1880380 + ... + 1891651.

It is an arithmetic number, because the mean of its divisors is an integer number (3102496320).

Almost surely, 2^21259166716 is an apocalyptic number.

It is an amenable number.

21259166716 is a deficient number, since it is larger than the sum of its proper divisors (15970789124).

21259166716 is a wasteful number, since it uses less digits than its factorization.

21259166716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3773444 (or 3773442 counting only the distinct ones).

The product of its digits is 272160, while the sum is 46.

The spelling of 21259166716 in words is "twenty-one billion, two hundred fifty-nine million, one hundred sixty-six thousand, seven hundred sixteen".