1245431809 has 2 divisors, whose sum is σ = 1245431810. Its totient is φ = 1245431808.

The previous prime is 1245431797. The next prime is 1245431821. The reversal of 1245431809 is 9081345421.

It is a balanced prime because it is at equal distance from previous prime (1245431797) and next prime (1245431821).

It can be written as a sum of positive squares in only one way, i.e., 1228292209 + 17139600 = 35047^2 + 4140^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1245431809 is a prime.

It is a super-2 number, since 2×1245431809² = 3102200781738024962, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1245431839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 622715904 + 622715905.

It is an arithmetic number, because the mean of its divisors is an integer number (622715905).

Almost surely, 2^1245431809 is an apocalyptic number.

It is an amenable number.

1245431809 is a deficient number, since it is larger than the sum of its proper divisors (1).

1245431809 is an equidigital number, since it uses as much as digits as its factorization.

1245431809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 1245431809 is about 35290.6759498880. The cubic root of 1245431809 is about 1075.9034939796.

The spelling of 1245431809 in words is "one billion, two hundred forty-five million, four hundred thirty-one thousand, eight hundred nine".