656471879669 has 2 divisors, whose sum is σ = 656471879670. Its totient is φ = 656471879668.

The previous prime is 656471879663. The next prime is 656471879731. The reversal of 656471879669 is 966978174656.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 584292072100 + 72179807569 = 764390^2 + 268663^2 .

It is a cyclic number.

It is not a de Polignac number, because 656471879669 - 2⁴ = 656471879653 is a prime.

It is a super-2 number, since 2×656471879669² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 656471879596 and 656471879605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (656471879663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328235939834 + 328235939835.

It is an arithmetic number, because the mean of its divisors is an integer number (328235939835).

Almost surely, 2^656471879669 is an apocalyptic number.

It is an amenable number.

656471879669 is a deficient number, since it is larger than the sum of its proper divisors (1).

656471879669 is an equidigital number, since it uses as much as digits as its factorization.

656471879669 is an evil number, because the sum of its binary digits is even.

The product of its digits is 823011840, while the sum is 74.

The spelling of 656471879669 in words is "six hundred fifty-six billion, four hundred seventy-one million, eight hundred seventy-nine thousand, six hundred sixty-nine".