209942680 has 16 divisors (see below), whose sum is σ = 472371120. Its totient is φ = 83977056.

The previous prime is 209942653. The next prime is 209942713. The reversal of 209942680 is 86249902.

It is a Harshad number since it is a multiple of its sum of digits (40), and also a Moran number because the ratio is a prime number: 5248567 = 209942680 / (2 + 0 + 9 + 9 + 4 + 2 + 6 + 8 + 0).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2624244 + ... + 2624323.

It is an arithmetic number, because the mean of its divisors is an integer number (29523195).

Almost surely, 2^209942680 is an apocalyptic number.

209942680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

209942680 is an abundant number, since it is smaller than the sum of its proper divisors (262428440).

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

209942680 is a wasteful number, since it uses less digits than its factorization.

209942680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5248578 (or 5248574 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 40.

The square root of 209942680 is about 14489.3988833216. The cubic root of 209942680 is about 594.3381101001.

The spelling of 209942680 in words is "two hundred nine million, nine hundred forty-two thousand, six hundred eighty".