217420473155 has 16 divisors (see below), whose sum is σ = 270479308320. Its totient is φ = 167578908672.

The previous prime is 217420473113. The next prime is 217420473197. The reversal of 217420473155 is 551374024712.

It is an interprime number because it is at equal distance from previous prime (217420473113) and next prime (217420473197).

It is a cyclic number.

It is not a de Polignac number, because 217420473155 - 2⁶ = 217420473091 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1537694 + ... + 1673123.

It is an arithmetic number, because the mean of its divisors is an integer number (16904956770).

Almost surely, 2^217420473155 is an apocalyptic number.

217420473155 is a deficient number, since it is larger than the sum of its proper divisors (53058835165).

217420473155 is a wasteful number, since it uses less digits than its factorization.

217420473155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3211318.

The product of its (nonzero) digits is 235200, while the sum is 41.

Adding to 217420473155 its reverse (551374024712), we get a palindrome (768794497867).

The spelling of 217420473155 in words is "two hundred seventeen billion, four hundred twenty million, four hundred seventy-three thousand, one hundred fifty-five".