172020550665 has 16 divisors (see below), whose sum is σ = 278548941888. Its totient is φ = 90638940096.

The previous prime is 172020550661. The next prime is 172020550693. The reversal of 172020550665 is 566055020271.

It is not a de Polignac number, because 172020550665 - 2² = 172020550661 is a prime.

It is not an unprimeable number, because it can be changed into a prime (172020550661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 69083314 + ... + 69085803.

It is an arithmetic number, because the mean of its divisors is an integer number (17409308868).

Almost surely, 2^172020550665 is an apocalyptic number.

172020550665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

172020550665 is a deficient number, since it is larger than the sum of its proper divisors (106528391223).

172020550665 is a wasteful number, since it uses less digits than its factorization.

172020550665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138169208.

The product of its (nonzero) digits is 126000, while the sum is 39.

The spelling of 172020550665 in words is "one hundred seventy-two billion, twenty million, five hundred fifty thousand, six hundred sixty-five".