20172122 has 4 divisors (see below), whose sum is σ = 30258186. Its totient is φ = 10086060.

The previous prime is 20172121. The next prime is 20172137. The reversal of 20172122 is 22127102.

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

It can be written as a sum of positive squares in only one way, i.e., 14969161 + 5202961 = 3869^2 + 2281^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20172122.

It is not an unprimeable number, because it can be changed into a prime (20172121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5043029 + ... + 5043032.

Almost surely, 2^20172122 is an apocalyptic number.

20172122 is a deficient number, since it is larger than the sum of its proper divisors (10086064).

20172122 is a wasteful number, since it uses less digits than its factorization.

20172122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10086063.

The product of its (nonzero) digits is 112, while the sum is 17.

The square root of 20172122 is about 4491.3385532600. The cubic root of 20172122 is about 272.2182234469.

Adding to 20172122 its reverse (22127102), we get a palindrome (42299224).

The spelling of 20172122 in words is "twenty million, one hundred seventy-two thousand, one hundred twenty-two".