21045818678 has 24 divisors (see below), whose sum is σ = 33994397352. Its totient is φ = 9768225024.

The previous prime is 21045818671. The next prime is 21045818683. The reversal of 21045818678 is 87681854012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21045818671) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 207200 + ... + 291587.

It is an arithmetic number, because the mean of its divisors is an integer number (1416433223).

Almost surely, 2^21045818678 is an apocalyptic number.

21045818678 is a deficient number, since it is larger than the sum of its proper divisors (12948578674).

21045818678 is a wasteful number, since it uses less digits than its factorization.

21045818678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 498896 (or 498879 counting only the distinct ones).

The product of its (nonzero) digits is 860160, while the sum is 50.

The spelling of 21045818678 in words is "twenty-one billion, forty-five million, eight hundred eighteen thousand, six hundred seventy-eight".