656747969 has 8 divisors (see below), whose sum is σ = 659436648. Its totient is φ = 654065280.

The previous prime is 656747953. The next prime is 656748017. The reversal of 656747969 is 969747656.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 16000000 + 640747969 = 4000^2 + 25313^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 656747969 - 2⁴ = 656747953 is a prime.

It is a super-2 number, since 2×656747969² = 862635789571249922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (656747929) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 442709 + ... + 444189.

It is an arithmetic number, because the mean of its divisors is an integer number (82429581).

Almost surely, 2^656747969 is an apocalyptic number.

It is an amenable number.

656747969 is a deficient number, since it is larger than the sum of its proper divisors (2688679).

656747969 is a wasteful number, since it uses less digits than its factorization.

656747969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2995.

The product of its digits is 17146080, while the sum is 59.

The square root of 656747969 is about 25627.0944314801. The cubic root of 656747969 is about 869.2264092693.

The spelling of 656747969 in words is "six hundred fifty-six million, seven hundred forty-seven thousand, nine hundred sixty-nine".