209867490 has 192 divisors, whose sum is σ = 674697600. Its totient is φ = 46230912.

The previous prime is 209867473. The next prime is 209867491. The reversal of 209867490 is 94768902.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209867491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 383397 + ... + 383943.

It is an arithmetic number, because the mean of its divisors is an integer number (3514050).

Almost surely, 2^209867490 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 209867490, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (337348800).

209867490 is an abundant number, since it is smaller than the sum of its proper divisors (464830110).

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

209867490 is a wasteful number, since it uses less digits than its factorization.

209867490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 606 (or 593 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 209867490 is about 14486.8039953607. The cubic root of 209867490 is about 594.2671484794.

The spelling of 209867490 in words is "two hundred nine million, eight hundred sixty-seven thousand, four hundred ninety".