21788027655 has 16 divisors (see below), whose sum is σ = 35041475040. Its totient is φ = 11560071168.

The previous prime is 21788027629. The next prime is 21788027683. The reversal of 21788027655 is 55672088712.

It is not a de Polignac number, because 21788027655 - 2¹² = 21788023559 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21788027598 and 21788027607.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 3760150 + ... + 3765939.

It is an arithmetic number, because the mean of its divisors is an integer number (2190092190).

Almost surely, 2^21788027655 is an apocalyptic number.

21788027655 is a deficient number, since it is larger than the sum of its proper divisors (13253447385).

21788027655 is a wasteful number, since it uses less digits than its factorization.

21788027655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7526290.

The product of its (nonzero) digits is 1881600, while the sum is 51.

The spelling of 21788027655 in words is "twenty-one billion, seven hundred eighty-eight million, twenty-seven thousand, six hundred fifty-five".