686387601 has 45 divisors (see below), whose sum is σ = 1065973579. Its totient is φ = 440143200.

The previous prime is 686387593. The next prime is 686387609. The reversal of 686387601 is 106783686.

The square root of 686387601 is 26199.

It is a perfect power (a square), and thus also a powerful number.

686387601 is a `hidden beast` number, since 6 + 8 + 6 + 38 + 7 + 601 = 666.

It is an interprime number because it is at equal distance from previous prime (686387593) and next prime (686387609).

It can be written as a sum of positive squares in only one way, i.e., 33074001 + 653313600 = 5751^2 + 25560^2 .

It is not a de Polignac number, because 686387601 - 2³ = 686387593 is a prime.

It is a super-2 number, since 2×686387601² = 942255877613070402, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (686387609) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 9667396 + ... + 9667466.

Almost surely, 2^686387601 is an apocalyptic number.

686387601 is the 26199-th square number.

686387601 is the 13100-th centered octagonal number.

It is an amenable number.

686387601 is a deficient number, since it is larger than the sum of its proper divisors (379585978).

686387601 is an frugal number, since it uses more digits than its factorization.

686387601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236 (or 115 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The cubic root of 686387601 is about 882.1108079581.

The spelling of 686387601 in words is "six hundred eighty-six million, three hundred eighty-seven thousand, six hundred one".