21864155955 has 8 divisors (see below), whose sum is σ = 34982649552. Its totient is φ = 11660883168.

The previous prime is 21864155953. The next prime is 21864155959. The reversal of 21864155955 is 55955146812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21864155955 - 2¹ = 21864155953 is a prime.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 21864155898 and 21864155907.

It is not an unprimeable number, because it can be changed into a prime (21864155953) 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, 728805184 + ... + 728805213.

It is an arithmetic number, because the mean of its divisors is an integer number (4372831194).

Almost surely, 2^21864155955 is an apocalyptic number.

21864155955 is a deficient number, since it is larger than the sum of its proper divisors (13118493597).

21864155955 is a wasteful number, since it uses less digits than its factorization.

21864155955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1457610405.

The product of its digits is 2160000, while the sum is 51.

The spelling of 21864155955 in words is "twenty-one billion, eight hundred sixty-four million, one hundred fifty-five thousand, nine hundred fifty-five".