21986745878 has 8 divisors (see below), whose sum is σ = 32984214240. Its totient is φ = 10992007800.

The previous prime is 21986745839. The next prime is 21986745901. The reversal of 21986745878 is 87854768912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 662318 + ... + 694721.

It is an arithmetic number, because the mean of its divisors is an integer number (4123026780).

Almost surely, 2^21986745878 is an apocalyptic number.

21986745878 is a deficient number, since it is larger than the sum of its proper divisors (10997468362).

21986745878 is a wasteful number, since it uses less digits than its factorization.

21986745878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1365142.

The product of its digits is 54190080, while the sum is 65.

The spelling of 21986745878 in words is "twenty-one billion, nine hundred eighty-six million, seven hundred forty-five thousand, eight hundred seventy-eight".