245107781 has 2 divisors, whose sum is σ = 245107782. Its totient is φ = 245107780.

The previous prime is 245107777. The next prime is 245107813. The reversal of 245107781 is 187701542.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 230736100 + 14371681 = 15190^2 + 3791^2 .

It is a cyclic number.

It is not a de Polignac number, because 245107781 - 2² = 245107777 is a prime.

It is a super-2 number, since 2×245107781² = 120155648613487922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (245107081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 122553890 + 122553891.

It is an arithmetic number, because the mean of its divisors is an integer number (122553891).

Almost surely, 2^245107781 is an apocalyptic number.

It is an amenable number.

245107781 is a deficient number, since it is larger than the sum of its proper divisors (1).

245107781 is an equidigital number, since it uses as much as digits as its factorization.

245107781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15680, while the sum is 35.

The square root of 245107781 is about 15655.9184016780. The cubic root of 245107781 is about 625.8242190363.

The spelling of 245107781 in words is "two hundred forty-five million, one hundred seven thousand, seven hundred eighty-one".