1241217781 has 2 divisors, whose sum is σ = 1241217782. Its totient is φ = 1241217780.

The previous prime is 1241217739. The next prime is 1241217797. The reversal of 1241217781 is 1877121421.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1236155281 + 5062500 = 35159^2 + 2250^2 .

It is a cyclic number.

It is not a de Polignac number, because 1241217781 - 2²⁷ = 1107000053 is a prime.

It is a super-2 number, since 2×1241217781² = 3081243159741127922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1241212781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 620608890 + 620608891.

It is an arithmetic number, because the mean of its divisors is an integer number (620608891).

Almost surely, 2^1241217781 is an apocalyptic number.

It is an amenable number.

1241217781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1241217781 is an equidigital number, since it uses as much as digits as its factorization.

1241217781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6272, while the sum is 34.

The square root of 1241217781 is about 35230.9208082900. The cubic root of 1241217781 is about 1074.6886514239.

The spelling of 1241217781 in words is "one billion, two hundred forty-one million, two hundred seventeen thousand, seven hundred eighty-one".