313785781 has 2 divisors, whose sum is σ = 313785782. Its totient is φ = 313785780.

The previous prime is 313785767. The next prime is 313785793. The reversal of 313785781 is 187587313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 235622500 + 78163281 = 15350^2 + 8841^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-313785781 is a prime.

It is a super-2 number, since 2×313785781² = 196923032715559922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (313785761) 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 as a sum of consecutive naturals, namely, 156892890 + 156892891.

It is an arithmetic number, because the mean of its divisors is an integer number (156892891).

Almost surely, 2^313785781 is an apocalyptic number.

It is an amenable number.

313785781 is a deficient number, since it is larger than the sum of its proper divisors (1).

313785781 is an equidigital number, since it uses as much as digits as its factorization.

313785781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 141120, while the sum is 43.

The square root of 313785781 is about 17713.9995766061. Note that the first 3 decimals coincide. The cubic root of 313785781 is about 679.5338363552.

The spelling of 313785781 in words is "three hundred thirteen million, seven hundred eighty-five thousand, seven hundred eighty-one".