209040860 has 36 divisors (see below), whose sum is σ = 510659352. Its totient is φ = 71670816.

The previous prime is 209040833. The next prime is 209040877. The reversal of 209040860 is 68040902.

It is a super-2 number, since 2×209040860² = 87396162299079200, which contains 22 as substring.

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 11 ways as a sum of consecutive naturals, for example, 105674 + ... + 107633.

It is an arithmetic number, because the mean of its divisors is an integer number (14184982).

Almost surely, 2^209040860 is an apocalyptic number.

209040860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

209040860 is an abundant number, since it is smaller than the sum of its proper divisors (301618492).

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

209040860 is a wasteful number, since it uses less digits than its factorization.

209040860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213330 (or 213321 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 209040860 is about 14458.2453983877. The cubic root of 209040860 is about 593.4858849700.

The spelling of 209040860 in words is "two hundred nine million, forty thousand, eight hundred sixty".