685309290 has 64 divisors (see below), whose sum is σ = 1735171200. Its totient is φ = 172744704.

The previous prime is 685309283. The next prime is 685309297. The reversal of 685309290 is 92903586.

It is an interprime number because it is at equal distance from previous prime (685309283) and next prime (685309297).

It is not an unprimeable number, because it can be changed into a prime (685309297) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 323274 + ... + 325386.

It is an arithmetic number, because the mean of its divisors is an integer number (27112050).

Almost surely, 2^685309290 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 685309290, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (867585600).

685309290 is an abundant number, since it is smaller than the sum of its proper divisors (1049861910).

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

685309290 is a wasteful number, since it uses less digits than its factorization.

685309290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2711.

The product of its (nonzero) digits is 116640, while the sum is 42.

The square root of 685309290 is about 26178.4126715124. The cubic root of 685309290 is about 881.6486355034.

The spelling of 685309290 in words is "six hundred eighty-five million, three hundred nine thousand, two hundred ninety".