1242123761 has 2 divisors, whose sum is σ = 1242123762. Its totient is φ = 1242123760.

The previous prime is 1242123691. The next prime is 1242123767. The reversal of 1242123761 is 1673212421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1172651536 + 69472225 = 34244^2 + 8335^2 .

It is an emirp because it is prime and its reverse (1673212421) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1242123761 - 2¹⁰ = 1242122737 is a prime.

It is not a weakly prime, because it can be changed into another prime (1242123767) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621061880 + 621061881.

It is an arithmetic number, because the mean of its divisors is an integer number (621061881).

Almost surely, 2^1242123761 is an apocalyptic number.

It is an amenable number.

1242123761 is a deficient number, since it is larger than the sum of its proper divisors (1).

1242123761 is an equidigital number, since it uses as much as digits as its factorization.

1242123761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4032, while the sum is 29.

The square root of 1242123761 is about 35243.7762023311. The cubic root of 1242123761 is about 1074.9500639505.

The spelling of 1242123761 in words is "one billion, two hundred forty-two million, one hundred twenty-three thousand, seven hundred sixty-one".