209131398 has 48 divisors (see below), whose sum is σ = 518937120. Its totient is φ = 59626368.

The previous prime is 209131381. The next prime is 209131409. The reversal of 209131398 is 893131902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 70236 + ... + 73152.

It is an arithmetic number, because the mean of its divisors is an integer number (10811190).

Almost surely, 2^209131398 is an apocalyptic number.

209131398 is an abundant number, since it is smaller than the sum of its proper divisors (309805722).

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

209131398 is a wasteful number, since it uses less digits than its factorization.

209131398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3501 (or 3498 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 209131398 is about 14461.3760756022. The cubic root of 209131398 is about 593.5715544566.

It can be divided in two parts, 2091 and 31398, that added together give a square (33489 = 183²).

The spelling of 209131398 in words is "two hundred nine million, one hundred thirty-one thousand, three hundred ninety-eight".