21259166782 has 32 divisors (see below), whose sum is σ = 36586872000. Its totient is φ = 9075483648.

The previous prime is 21259166771. The next prime is 21259166809. The reversal of 21259166782 is 28766195212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6706894 + ... + 6710062.

It is an arithmetic number, because the mean of its divisors is an integer number (1143339750).

Almost surely, 2^21259166782 is an apocalyptic number.

21259166782 is a deficient number, since it is larger than the sum of its proper divisors (15327705218).

21259166782 is a wasteful number, since it uses less digits than its factorization.

21259166782 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4900.

The product of its digits is 725760, while the sum is 49.

The spelling of 21259166782 in words is "twenty-one billion, two hundred fifty-nine million, one hundred sixty-six thousand, seven hundred eighty-two".