656723861 has 2 divisors, whose sum is σ = 656723862. Its totient is φ = 656723860.

The previous prime is 656723843. The next prime is 656723863. The reversal of 656723861 is 168327656.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 649995025 + 6728836 = 25495^2 + 2594^2 .

It is a cyclic number.

It is not a de Polignac number, because 656723861 - 2⁶ = 656723797 is a prime.

Together with 656723863, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (656723863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328361930 + 328361931.

It is an arithmetic number, because the mean of its divisors is an integer number (328361931).

Almost surely, 2^656723861 is an apocalyptic number.

It is an amenable number.

656723861 is a deficient number, since it is larger than the sum of its proper divisors (1).

656723861 is an equidigital number, since it uses as much as digits as its factorization.

656723861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 362880, while the sum is 44.

The square root of 656723861 is about 25626.6240656080. The cubic root of 656723861 is about 869.2157732426.

The spelling of 656723861 in words is "six hundred fifty-six million, seven hundred twenty-three thousand, eight hundred sixty-one".