217648226451 has 4 divisors (see below), whose sum is σ = 290197635272. Its totient is φ = 145098817632.

The previous prime is 217648226437. The next prime is 217648226479. The reversal of 217648226451 is 154622846712.

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

It is not a de Polignac number, because 217648226451 - 2¹⁸ = 217647964307 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 217648226451.

It is not an unprimeable number, because it can be changed into a prime (217648226491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36274704406 + ... + 36274704411.

It is an arithmetic number, because the mean of its divisors is an integer number (72549408818).

Almost surely, 2^217648226451 is an apocalyptic number.

217648226451 is a deficient number, since it is larger than the sum of its proper divisors (72549408821).

217648226451 is an equidigital number, since it uses as much as digits as its factorization.

217648226451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72549408820.

The product of its digits is 1290240, while the sum is 48.

The spelling of 217648226451 in words is "two hundred seventeen billion, six hundred forty-eight million, two hundred twenty-six thousand, four hundred fifty-one".