21018075786 has 48 divisors (see below), whose sum is σ = 49157746560. Its totient is φ = 6470328480.

The previous prime is 21018075773. The next prime is 21018075791. The reversal of 21018075786 is 68757081012.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 863310 + ... + 887321.

It is an arithmetic number, because the mean of its divisors is an integer number (1024119720).

Almost surely, 2^21018075786 is an apocalyptic number.

21018075786 is an abundant number, since it is smaller than the sum of its proper divisors (28139670774).

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

21018075786 is a wasteful number, since it uses less digits than its factorization.

21018075786 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1750691 (or 1750688 counting only the distinct ones).

The product of its (nonzero) digits is 188160, while the sum is 45.

The spelling of 21018075786 in words is "twenty-one billion, eighteen million, seventy-five thousand, seven hundred eighty-six".