999872122 has 4 divisors (see below), whose sum is σ = 1499808186. Its totient is φ = 499936060.

The previous prime is 999872059. The next prime is 999872129. The reversal of 999872122 is 221278999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 221278999 = 10163 ⋅21773.

It can be written as a sum of positive squares in only one way, i.e., 562685841 + 437186281 = 23721^2 + 20909^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a pancake number, because a pancake can be divided into 999872122 parts by 44718 straight cuts.

It is not an unprimeable number, because it can be changed into a prime (999872129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 249968029 + ... + 249968032.

Almost surely, 2^999872122 is an apocalyptic number.

999872122 is a deficient number, since it is larger than the sum of its proper divisors (499936064).

999872122 is a wasteful number, since it uses less digits than its factorization.

999872122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 499936063.

The product of its digits is 326592, while the sum is 49.

The square root of 999872122 is about 31620.7546083265. The cubic root of 999872122 is about 999.9573721829.

The spelling of 999872122 in words is "nine hundred ninety-nine million, eight hundred seventy-two thousand, one hundred twenty-two".