21978274726 has 16 divisors (see below), whose sum is σ = 34406402400. Its totient is φ = 10509630208.

The previous prime is 21978274709. The next prime is 21978274733. The reversal of 21978274726 is 62747287912.

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 7 ways as a sum of consecutive naturals, for example, 271980 + ... + 343408.

It is an arithmetic number, because the mean of its divisors is an integer number (2150400150).

Almost surely, 2^21978274726 is an apocalyptic number.

21978274726 is a deficient number, since it is larger than the sum of its proper divisors (12428127674).

21978274726 is a wasteful number, since it uses less digits than its factorization.

21978274726 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78143.

The product of its digits is 4741632, while the sum is 55.

The spelling of 21978274726 in words is "twenty-one billion, nine hundred seventy-eight million, two hundred seventy-four thousand, seven hundred twenty-six".