656713781 has 2 divisors, whose sum is σ = 656713782. Its totient is φ = 656713780.

The previous prime is 656713763. The next prime is 656713789. The reversal of 656713781 is 187317656.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 614593681 + 42120100 = 24791^2 + 6490^2 .

It is a cyclic number.

It is not a de Polignac number, because 656713781 - 2¹⁰ = 656712757 is a prime.

It is a super-2 number, since 2×656713781² = 862545980310631922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (656713789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328356890 + 328356891.

It is an arithmetic number, because the mean of its divisors is an integer number (328356891).

Almost surely, 2^656713781 is an apocalyptic number.

It is an amenable number.

656713781 is a deficient number, since it is larger than the sum of its proper divisors (1).

656713781 is an equidigital number, since it uses as much as digits as its factorization.

656713781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 211680, while the sum is 44.

The square root of 656713781 is about 25626.4273943911. The cubic root of 656713781 is about 869.2113260463.

The spelling of 656713781 in words is "six hundred fifty-six million, seven hundred thirteen thousand, seven hundred eighty-one".