656891641 has 4 divisors (see below), whose sum is σ = 750733312. Its totient is φ = 563049972.

The previous prime is 656891629. The next prime is 656891671. The reversal of 656891641 is 146198656.

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 656891641 - 2⁷ = 656891513 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 656891591 and 656891600.

It is not an unprimeable number, because it can be changed into a prime (656891671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46920825 + ... + 46920838.

It is an arithmetic number, because the mean of its divisors is an integer number (187683328).

Almost surely, 2^656891641 is an apocalyptic number.

It is an amenable number.

656891641 is a deficient number, since it is larger than the sum of its proper divisors (93841671).

656891641 is an equidigital number, since it uses as much as digits as its factorization.

656891641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93841670.

The product of its digits is 311040, while the sum is 46.

The square root of 656891641 is about 25629.8974051790. The cubic root of 656891641 is about 869.2897894379.

The spelling of 656891641 in words is "six hundred fifty-six million, eight hundred ninety-one thousand, six hundred forty-one".