21866835155 has 8 divisors (see below), whose sum is σ = 28625675184. Its totient is φ = 15903152800.

The previous prime is 21866835139. The next prime is 21866835173. The reversal of 21866835155 is 55153866812.

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

It is not a de Polignac number, because 21866835155 - 2⁴ = 21866835139 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 198789356 + ... + 198789465.

It is an arithmetic number, because the mean of its divisors is an integer number (3578209398).

Almost surely, 2^21866835155 is an apocalyptic number.

21866835155 is a deficient number, since it is larger than the sum of its proper divisors (6758840029).

21866835155 is a wasteful number, since it uses less digits than its factorization.

21866835155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397578837.

The product of its digits is 1728000, while the sum is 50.

The spelling of 21866835155 in words is "twenty-one billion, eight hundred sixty-six million, eight hundred thirty-five thousand, one hundred fifty-five".