656601 has 16 divisors (see below), whose sum is σ = 969408.
Its totient is φ = 392000.
The previous prime is 656599. The next prime is 656603. The reversal of 656601 is 106656.
Subtracting from 656601 its reverse (106656), we obtain a palindrome (549945).
It can be divided in two parts, 65 and 6601, that added together give a palindrome (6666).
It is an interprime number because it is at equal distance from previous prime (656599) and next prime (656603).
It is a 2-Lehmer number, since φ(656601) divides (656601-1)2.
It is a cyclic number.
It is a Carmichael number.
It is not a de Polignac number, because 656601 - 21 = 656599 is a prime.
It is a super-2 number, since 2×6566012 = 862249746402, which contains 22 as substring.
It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.
656601 is a lucky number.
It is not an unprimeable number, because it can be changed into a prime (656603) 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, 3235 + ... + 3431.
It is an arithmetic number, because the mean of its divisors is an integer number (60588).
It is a Poulet number, since it divides 2656600-1.
2656601 is an apocalyptic number.
It is an amenable number.
656601 is a deficient number, since it is larger than the sum of its proper divisors (312807).
656601 is a wasteful number, since it uses less digits than its factorization.
656601 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 312.
The product of its (nonzero) digits is 1080, while the sum is 24.
The square root of 656601 is about 810.3092002440.
The cubic root of 656601 is about 86.9161565081.
The spelling of 656601 in words is "six hundred fifty-six thousand, six hundred one".