164778920505219 has 4 divisors (see below), whose sum is σ = 219705227340296. Its totient is φ = 109852613670144.

The previous prime is 164778920505203. The next prime is 164778920505239. The reversal of 164778920505219 is 912505029877461.

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

It is not a de Polignac number, because 164778920505219 - 2⁴ = 164778920505203 is a prime.

It is a super-2 number, since 2×164778920505219² (a number of 29 digits) contains 22 as substring.

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 164778920505219.

It is not an unprimeable number, because it can be changed into a prime (164778920505239) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27463153417534 + ... + 27463153417539.

It is an arithmetic number, because the mean of its divisors is an integer number (54926306835074).

Almost surely, 2^{164778920505219} is an apocalyptic number.

164778920505219 is a deficient number, since it is larger than the sum of its proper divisors (54926306835077).

164778920505219 is an equidigital number, since it uses as much as digits as its factorization.

164778920505219 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54926306835076.

The product of its (nonzero) digits is 76204800, while the sum is 66.

The spelling of 164778920505219 in words is "one hundred sixty-four trillion, seven hundred seventy-eight billion, nine hundred twenty million, five hundred five thousand, two hundred nineteen".