209442040 has 32 divisors (see below), whose sum is σ = 498966480. Its totient is φ = 78848512.

The previous prime is 209442029. The next prime is 209442059. The reversal of 209442040 is 40244902.

It is a junction number, because it is equal to n+sod(n) for n = 209441996 and 209442014.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 153322 + ... + 154681.

Almost surely, 2^209442040 is an apocalyptic number.

209442040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

209442040 is an abundant number, since it is smaller than the sum of its proper divisors (289524440).

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

209442040 is a wasteful number, since it uses less digits than its factorization.

209442040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308031 (or 308027 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 209442040 is about 14472.1124926529. The cubic root of 209442040 is about 593.8653044397.

Adding to 209442040 its reverse (40244902), we get a palindrome (249686942).

The spelling of 209442040 in words is "two hundred nine million, four hundred forty-two thousand, forty".