686390220 has 192 divisors, whose sum is σ = 2228244480. Its totient is φ = 175219200.

The previous prime is 686390197. The next prime is 686390261. The reversal of 686390220 is 22093686.

It is a super-2 number, since 2×686390220² = 942263068223296800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 2192784 + ... + 2193096.

It is an arithmetic number, because the mean of its divisors is an integer number (11605440).

Almost surely, 2^686390220 is an apocalyptic number.

686390220 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686390220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1114122240).

686390220 is an abundant number, since it is smaller than the sum of its proper divisors (1541854260).

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

686390220 is a wasteful number, since it uses less digits than its factorization.

686390220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 493 (or 485 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 686390220 is about 26199.0499827761. The cubic root of 686390220 is about 882.1119298923. Note that the first 3 decimals are identical.

The spelling of 686390220 in words is "six hundred eighty-six million, three hundred ninety thousand, two hundred twenty".