209689980 has 48 divisors (see below), whose sum is σ = 595413504. Its totient is φ = 55128640.

The previous prime is 209689969. The next prime is 209689993. The reversal of 209689980 is 89986902.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20352 + ... + 28871.

It is an arithmetic number, because the mean of its divisors is an integer number (12404448).

Almost surely, 2^209689980 is an apocalyptic number.

209689980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

209689980 is an abundant number, since it is smaller than the sum of its proper divisors (385723524).

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

209689980 is a wasteful number, since it uses less digits than its factorization.

209689980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49306 (or 49304 counting only the distinct ones).

The product of its (nonzero) digits is 559872, while the sum is 51.

The square root of 209689980 is about 14480.6760891887. The cubic root of 209689980 is about 594.0995536526.

The spelling of 209689980 in words is "two hundred nine million, six hundred eighty-nine thousand, nine hundred eighty".