21007678768 has 40 divisors (see below), whose sum is σ = 41447235600. Its totient is φ = 10312091904.

The previous prime is 21007678763. The next prime is 21007678781. The reversal of 21007678768 is 86787670012.

It is not an unprimeable number, because it can be changed into a prime (21007678763) by changing a digit.

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, 715318 + ... + 744106.

It is an arithmetic number, because the mean of its divisors is an integer number (1036180890).

Almost surely, 2^21007678768 is an apocalyptic number.

It is an amenable number.

21007678768 is a deficient number, since it is larger than the sum of its proper divisors (20439556832).

21007678768 is a wasteful number, since it uses less digits than its factorization.

21007678768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29629 (or 29623 counting only the distinct ones).

The product of its (nonzero) digits is 1580544, while the sum is 52.

The spelling of 21007678768 in words is "twenty-one billion, seven million, six hundred seventy-eight thousand, seven hundred sixty-eight".