128199842 has 4 divisors (see below), whose sum is σ = 192299766. Its totient is φ = 64099920.

The previous prime is 128199833. The next prime is 128199871. The reversal of 128199842 is 248991821.

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., 127938721 + 261121 = 11311^2 + 511^2 .

It is a junction number, because it is equal to n+sod(n) for n = 128199793 and 128199802.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32049959 + ... + 32049962.

Almost surely, 2^128199842 is an apocalyptic number.

128199842 is a deficient number, since it is larger than the sum of its proper divisors (64099924).

128199842 is an equidigital number, since it uses as much as digits as its factorization.

128199842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64099923.

The product of its digits is 82944, while the sum is 44.

The square root of 128199842 is about 11322.5369065417. The cubic root of 128199842 is about 504.2305597720.

The spelling of 128199842 in words is "one hundred twenty-eight million, one hundred ninety-nine thousand, eight hundred forty-two".