21908193782 has 16 divisors (see below), whose sum is σ = 34001745840. Its totient is φ = 10574417952.

The previous prime is 21908193767. The next prime is 21908193787. The reversal of 21908193782 is 28739180912.

It is a self number, because there is not a number n which added to its sum of digits gives 21908193782.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21908193787) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 311648 + ... + 375420.

It is an arithmetic number, because the mean of its divisors is an integer number (2125109115).

Almost surely, 2^21908193782 is an apocalyptic number.

21908193782 is a deficient number, since it is larger than the sum of its proper divisors (12093552058).

21908193782 is a wasteful number, since it uses less digits than its factorization.

21908193782 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69727.

The product of its (nonzero) digits is 435456, while the sum is 50.

The spelling of 21908193782 in words is "twenty-one billion, nine hundred eight million, one hundred ninety-three thousand, seven hundred eighty-two".