820172954918 has 4 divisors (see below), whose sum is σ = 1230259432380. Its totient is φ = 410086477458.

The previous prime is 820172954891. The next prime is 820172954927. The reversal of 820172954918 is 819459271028.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 205043238728 + ... + 205043238731.

It is an arithmetic number, because the mean of its divisors is an integer number (307564858095).

Almost surely, 2^820172954918 is an apocalyptic number.

820172954918 is a deficient number, since it is larger than the sum of its proper divisors (410086477462).

820172954918 is a wasteful number, since it uses less digits than its factorization.

820172954918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410086477461.

The product of its (nonzero) digits is 2903040, while the sum is 56.

The spelling of 820172954918 in words is "eight hundred twenty billion, one hundred seventy-two million, nine hundred fifty-four thousand, nine hundred eighteen".