199123456 has 60 divisors (see below), whose sum is σ = 462872718. Its totient is φ = 85327872.

The previous prime is 199123453. The next prime is 199123471. The reversal of 199123456 is 654321991.

It can be written as a sum of positive squares in only one way, i.e., 108493056 + 90630400 = 10416^2 + 9520^2 .

It is not an unprimeable number, because it can be changed into a prime (199123453) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 21120 + ... + 29056.

Almost surely, 2^199123456 is an apocalyptic number.

199123456 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 199123456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (231436359).

199123456 is an abundant number, since it is smaller than the sum of its proper divisors (263749262).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

199123456 is an frugal number, since it uses more digits than its factorization.

199123456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7969 (or 7946 counting only the distinct ones).

The product of its digits is 58320, while the sum is 40.

The square root of 199123456 is about 14111.1110831146. Note that the first 3 decimals coincide. The cubic root of 199123456 is about 583.9479530773.

The spelling of 199123456 in words is "one hundred ninety-nine million, one hundred twenty-three thousand, four hundred fifty-six".