656478601 has 4 divisors (see below), whose sum is σ = 657849600. Its totient is φ = 655107604.

The previous prime is 656478587. The next prime is 656478611. The reversal of 656478601 is 106874656.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 656478601 - 2⁵ = 656478569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (656478611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 684781 + ... + 685738.

It is an arithmetic number, because the mean of its divisors is an integer number (164462400).

Almost surely, 2^656478601 is an apocalyptic number.

It is an amenable number.

656478601 is a deficient number, since it is larger than the sum of its proper divisors (1370999).

656478601 is a wasteful number, since it uses less digits than its factorization.

656478601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1370998.

The product of its (nonzero) digits is 241920, while the sum is 43.

The square root of 656478601 is about 25621.8383610544. The cubic root of 656478601 is about 869.1075540365.

The spelling of 656478601 in words is "six hundred fifty-six million, four hundred seventy-eight thousand, six hundred one".