172218242320551 has 48 divisors (see below), whose sum is σ = 295724981348160. Its totient is φ = 94492005511680.

The previous prime is 172218242320433. The next prime is 172218242320571. The reversal of 172218242320551 is 155023242812271.

172218242320551 is a `hidden beast` number, since 1 + 7 + 2 + 2 + 18 + 2 + 423 + 205 + 5 + 1 = 666.

It is not a de Polignac number, because 172218242320551 - 2¹⁴ = 172218242304167 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 172218242320497 and 172218242320506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172218242320571) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 260063950 + ... + 260725323.

It is an arithmetic number, because the mean of its divisors is an integer number (6160937111420).

Almost surely, 2^{172218242320551} is an apocalyptic number.

172218242320551 is a deficient number, since it is larger than the sum of its proper divisors (123506739027609).

172218242320551 is a wasteful number, since it uses less digits than its factorization.

172218242320551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 520789496 (or 520789493 counting only the distinct ones).

The product of its (nonzero) digits is 537600, while the sum is 45.

The spelling of 172218242320551 in words is "one hundred seventy-two trillion, two hundred eighteen billion, two hundred forty-two million, three hundred twenty thousand, five hundred fifty-one".