656215601 has 4 divisors (see below), whose sum is σ = 663588900. Its totient is φ = 648842304.

The previous prime is 656215577. The next prime is 656215603. The reversal of 656215601 is 106512656.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 60855601 + 595360000 = 7801^2 + 24400^2 .

It is a cyclic number.

It is not a de Polignac number, because 656215601 - 2¹⁰ = 656214577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (656215603) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3686516 + ... + 3686693.

It is an arithmetic number, because the mean of its divisors is an integer number (165897225).

Almost surely, 2^656215601 is an apocalyptic number.

It is an amenable number.

656215601 is a deficient number, since it is larger than the sum of its proper divisors (7373299).

656215601 is an equidigital number, since it uses as much as digits as its factorization.

656215601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7373298.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 656215601 is about 25616.7055063683. The cubic root of 656215601 is about 868.9914772305.

The spelling of 656215601 in words is "six hundred fifty-six million, two hundred fifteen thousand, six hundred one".