18217275551 has 4 divisors (see below), whose sum is σ = 18266914272. Its totient is φ = 18167636832.

The previous prime is 18217275541. The next prime is 18217275569. The reversal of 18217275551 is 15557271281.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18217275551 - 2¹⁸ = 18217013407 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18217275541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24818810 + ... + 24819543.

It is an arithmetic number, because the mean of its divisors is an integer number (4566728568).

Almost surely, 2^18217275551 is an apocalyptic number.

18217275551 is a deficient number, since it is larger than the sum of its proper divisors (49638721).

18217275551 is an equidigital number, since it uses as much as digits as its factorization.

18217275551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49638720.

The product of its digits is 196000, while the sum is 44.

The spelling of 18217275551 in words is "eighteen billion, two hundred seventeen million, two hundred seventy-five thousand, five hundred fifty-one".