21195608216838 has 64 divisors (see below), whose sum is σ = 48754616601600. Its totient is φ = 6075400131360.

The previous prime is 21195608216791. The next prime is 21195608216891. The reversal of 21195608216838 is 83861280659112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12337068 + ... + 13949711.

It is an arithmetic number, because the mean of its divisors is an integer number (761790884400).

Almost surely, 2^{21195608216838} is an apocalyptic number.

21195608216838 is an abundant number, since it is smaller than the sum of its proper divisors (27559008384762).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21195608216838 is a wasteful number, since it uses less digits than its factorization.

21195608216838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26287457.

The product of its (nonzero) digits is 9953280, while the sum is 60.

The spelling of 21195608216838 in words is "twenty-one trillion, one hundred ninety-five billion, six hundred eight million, two hundred sixteen thousand, eight hundred thirty-eight".