21635378446 has 16 divisors (see below), whose sum is σ = 36360195120. Its totient is φ = 9568471680.

The previous prime is 21635378417. The next prime is 21635378473. The reversal of 21635378446 is 64487353612.

It is a self number, because there is not a number n which added to its sum of digits gives 21635378446.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13288731 + ... + 13290358.

It is an arithmetic number, because the mean of its divisors is an integer number (2272512195).

Almost surely, 2^21635378446 is an apocalyptic number.

21635378446 is a deficient number, since it is larger than the sum of its proper divisors (14724816674).

21635378446 is a wasteful number, since it uses less digits than its factorization.

21635378446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26579139.

The product of its digits is 2903040, while the sum is 49.

The spelling of 21635378446 in words is "twenty-one billion, six hundred thirty-five million, three hundred seventy-eight thousand, four hundred forty-six".