209676390 has 96 divisors (see below), whose sum is σ = 638648064. Its totient is φ = 43565760.

The previous prime is 209676361. The next prime is 209676391. The reversal of 209676390 is 93676902.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209676391) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9687 + ... + 22653.

It is an arithmetic number, because the mean of its divisors is an integer number (6652584).

Almost surely, 2^209676390 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 209676390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (319324032).

209676390 is an abundant number, since it is smaller than the sum of its proper divisors (428971674).

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

209676390 is a wasteful number, since it uses less digits than its factorization.

209676390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13002 (or 12995 counting only the distinct ones).

The product of its (nonzero) digits is 122472, while the sum is 42.

The square root of 209676390 is about 14480.2068355393. The cubic root of 209676390 is about 594.0867188518.

The spelling of 209676390 in words is "two hundred nine million, six hundred seventy-six thousand, three hundred ninety".