21936712786 has 4 divisors (see below), whose sum is σ = 32905069182. Its totient is φ = 10968356392.

The previous prime is 21936712771. The next prime is 21936712799. The reversal of 21936712786 is 68721763912.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 17767557025 + 4169155761 = 133295^2 + 64569^2 .

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 as a sum of consecutive naturals, namely, 5484178195 + ... + 5484178198.

Almost surely, 2^21936712786 is an apocalyptic number.

21936712786 is a deficient number, since it is larger than the sum of its proper divisors (10968356396).

21936712786 is a wasteful number, since it uses less digits than its factorization.

21936712786 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10968356395.

The product of its digits is 1524096, while the sum is 52.

The spelling of 21936712786 in words is "twenty-one billion, nine hundred thirty-six million, seven hundred twelve thousand, seven hundred eighty-six".