209121852 has 12 divisors (see below), whose sum is σ = 487951016. Its totient is φ = 69707280.

The previous prime is 209121851. The next prime is 209121917. The reversal of 209121852 is 258121902.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209121851) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8713399 + ... + 8713422.

Almost surely, 2^209121852 is an apocalyptic number.

It is an amenable number.

209121852 is an abundant number, since it is smaller than the sum of its proper divisors (278829164).

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

209121852 is a wasteful number, since it uses less digits than its factorization.

209121852 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17426828 (or 17426826 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 30.

The square root of 209121852 is about 14461.0460202573. The cubic root of 209121852 is about 593.5625229413.

Subtracting 209121852 from its reverse (258121902), we obtain a triangular number (49000050 = T₉₈₉₉).

The spelling of 209121852 in words is "two hundred nine million, one hundred twenty-one thousand, eight hundred fifty-two".