1243999997 has 2 divisors, whose sum is σ = 1243999998. Its totient is φ = 1243999996.

The previous prime is 1243999987. The next prime is 1244000003. The reversal of 1243999997 is 7999993421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1211805721 + 32194276 = 34811^2 + 5674^2 .

It is a cyclic number.

It is not a de Polignac number, because 1243999997 - 2¹⁴ = 1243983613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1243999987) 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, 621999998 + 621999999.

It is an arithmetic number, because the mean of its divisors is an integer number (621999999).

Almost surely, 2^1243999997 is an apocalyptic number.

It is an amenable number.

1243999997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243999997 is an equidigital number, since it uses as much as digits as its factorization.

1243999997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9920232, while the sum is 62.

The square root of 1243999997 is about 35270.3841345682. The cubic root of 1243999997 is about 1075.4910313456.

The spelling of 1243999997 in words is "one billion, two hundred forty-three million, nine hundred ninety-nine thousand, nine hundred ninety-seven".