20172322555 has 32 divisors (see below), whose sum is σ = 30189358080. Its totient is φ = 12571009920.

The previous prime is 20172322543. The next prime is 20172322561. The reversal of 20172322555 is 55522327102.

It is not a de Polignac number, because 20172322555 - 2²⁹ = 19635451643 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20172322555.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1659841 + ... + 1671949.

It is an arithmetic number, because the mean of its divisors is an integer number (943417440).

Almost surely, 2^20172322555 is an apocalyptic number.

20172322555 is a deficient number, since it is larger than the sum of its proper divisors (10017035525).

20172322555 is a wasteful number, since it uses less digits than its factorization.

20172322555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16459.

The product of its (nonzero) digits is 42000, while the sum is 34.

Adding to 20172322555 its reverse (55522327102), we get a palindrome (75694649657).

The spelling of 20172322555 in words is "twenty billion, one hundred seventy-two million, three hundred twenty-two thousand, five hundred fifty-five".