172009822 has 4 divisors (see below), whose sum is σ = 258014736. Its totient is φ = 86004910.

The previous prime is 172009811. The next prime is 172009823. The reversal of 172009822 is 228900271.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 228900271 = 11197 ⋅20443.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172009823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43002454 + ... + 43002457.

It is an arithmetic number, because the mean of its divisors is an integer number (64503684).

Almost surely, 2^172009822 is an apocalyptic number.

172009822 is a deficient number, since it is larger than the sum of its proper divisors (86004914).

172009822 is an equidigital number, since it uses as much as digits as its factorization.

172009822 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86004913.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 172009822 is about 13115.2515034978. The cubic root of 172009822 is about 556.1403623163.

The spelling of 172009822 in words is "one hundred seventy-two million, nine thousand, eight hundred twenty-two".