21788938767 has 16 divisors (see below), whose sum is σ = 29422820448. Its totient is φ = 14341324800.

The previous prime is 21788938763. The next prime is 21788938817. The reversal of 21788938767 is 76783988712.

It is not a de Polignac number, because 21788938767 - 2² = 21788938763 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21788938698 and 21788938707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21788938763) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5103 + ... + 208815.

It is an arithmetic number, because the mean of its divisors is an integer number (1838926278).

Almost surely, 2^21788938767 is an apocalyptic number.

21788938767 is a deficient number, since it is larger than the sum of its proper divisors (7633881681).

21788938767 is a wasteful number, since it uses less digits than its factorization.

21788938767 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204170.

The product of its digits is 56899584, while the sum is 66.

The spelling of 21788938767 in words is "twenty-one billion, seven hundred eighty-eight million, nine hundred thirty-eight thousand, seven hundred sixty-seven".