209423842 has 4 divisors (see below), whose sum is σ = 314135766. Its totient is φ = 104711920.

The previous prime is 209423783. The next prime is 209423887. The reversal of 209423842 is 248324902.

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., 125865961 + 83557881 = 11219^2 + 9141^2 .

It is a junction number, because it is equal to n+sod(n) for n = 209423798 and 209423807.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 52355959 + ... + 52355962.

Almost surely, 2^209423842 is an apocalyptic number.

209423842 is a deficient number, since it is larger than the sum of its proper divisors (104711924).

209423842 is a wasteful number, since it uses less digits than its factorization.

209423842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104711923.

The product of its (nonzero) digits is 27648, while the sum is 34.

The square root of 209423842 is about 14471.4837525390. The cubic root of 209423842 is about 593.8481040186.

The spelling of 209423842 in words is "two hundred nine million, four hundred twenty-three thousand, eight hundred forty-two".