686201620 has 48 divisors (see below), whose sum is σ = 1562374800. Its totient is φ = 251652096.

The previous prime is 686201609. The next prime is 686201623. The reversal of 686201620 is 26102686.

It can be written as a sum of positive squares in 8 ways, for example, as 32581264 + 653620356 = 5708^2 + 25566^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686201623) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29884 + ... + 47596.

It is an arithmetic number, because the mean of its divisors is an integer number (32549475).

Almost surely, 2^686201620 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686201620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (781187400).

686201620 is an abundant number, since it is smaller than the sum of its proper divisors (876173180).

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

686201620 is a wasteful number, since it uses less digits than its factorization.

686201620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17884 (or 17882 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 686201620 is about 26195.4503683369. The cubic root of 686201620 is about 882.0311296201.

The spelling of 686201620 in words is "six hundred eighty-six million, two hundred one thousand, six hundred twenty".