686021400 has 480 divisors, whose sum is σ = 2625099840. Its totient is φ = 165335040.

The previous prime is 686021387. The next prime is 686021411. The reversal of 686021400 is 4120686.

686021400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×686021400² = 941250722515920000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 12943774 + ... + 12943826.

It is an arithmetic number, because the mean of its divisors is an integer number (5468958).

Almost surely, 2^686021400 is an apocalyptic number.

686021400 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 686021400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1312549920).

686021400 is an abundant number, since it is smaller than the sum of its proper divisors (1939078440).

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

686021400 is a wasteful number, since it uses less digits than its factorization.

686021400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145 (or 127 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 686021400 is about 26192.0102321300. The cubic root of 686021400 is about 881.9539056850.

The spelling of 686021400 in words is "six hundred eighty-six million, twenty-one thousand, four hundred".