217812142155545 has 64 divisors (see below), whose sum is σ = 325315143820800. Its totient is φ = 136601310504960.

The previous prime is 217812142155541. The next prime is 217812142155551. The reversal of 217812142155545 is 545551241218712.

217812142155545 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 217812142155545 - 2² = 217812142155541 is a prime.

It is not an unprimeable number, because it can be changed into a prime (217812142155541) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 170247077 + ... + 171521693.

It is an arithmetic number, because the mean of its divisors is an integer number (5083049122200).

Almost surely, 2^{217812142155545} is an apocalyptic number.

It is an amenable number.

217812142155545 is a deficient number, since it is larger than the sum of its proper divisors (107503001665255).

217812142155545 is a wasteful number, since it uses less digits than its factorization.

217812142155545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1283538.

The product of its digits is 4480000, while the sum is 53.

The spelling of 217812142155545 in words is "two hundred seventeen trillion, eight hundred twelve billion, one hundred forty-two million, one hundred fifty-five thousand, five hundred forty-five".