217849263853 has 8 divisors (see below), whose sum is σ = 236101213208. Its totient is φ = 199810787904.

The previous prime is 217849263823. The next prime is 217849263871. The reversal of 217849263853 is 358362948712.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 11518011684 + 206331252169 = 107322^2 + 454237^2 .

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

It is not a de Polignac number, because 217849263853 - 2¹³ = 217849255661 is a prime.

It is a super-2 number, since 2×217849263853² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217849263823) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53366226 + ... + 53370307.

It is an arithmetic number, because the mean of its divisors is an integer number (29512651651).

Almost surely, 2^217849263853 is an apocalyptic number.

It is an amenable number.

217849263853 is a deficient number, since it is larger than the sum of its proper divisors (18251949355).

217849263853 is a wasteful number, since it uses less digits than its factorization.

217849263853 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106736703.

The product of its digits is 17418240, while the sum is 58.

The spelling of 217849263853 in words is "two hundred seventeen billion, eight hundred forty-nine million, two hundred sixty-three thousand, eight hundred fifty-three".