686369520 has 120 divisors (see below), whose sum is σ = 2361380112. Its totient is φ = 178560000.

The previous prime is 686369503. The next prime is 686369527. The reversal of 686369520 is 25963686.

It is a happy number.

686369520 is a `hidden beast` number, since 6 + 8 + 63 + 69 + 520 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×686369520² = 942206235970060800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686369527) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17895 + ... + 41145.

Almost surely, 2^686369520 is an apocalyptic number.

686369520 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 686369520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1180690056).

686369520 is an abundant number, since it is smaller than the sum of its proper divisors (1675010592).

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

686369520 is a wasteful number, since it uses less digits than its factorization.

686369520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23311 (or 23302 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The square root of 686369520 is about 26198.6549273050. The cubic root of 686369520 is about 882.1030622929.

The spelling of 686369520 in words is "six hundred eighty-six million, three hundred sixty-nine thousand, five hundred twenty".