1245145391 has 4 divisors (see below), whose sum is σ = 1423023312. Its totient is φ = 1067267472.

The previous prime is 1245145387. The next prime is 1245145397. The reversal of 1245145391 is 1935415421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1935415421 = 3769 ⋅513509.

It is a cyclic number.

It is not a de Polignac number, because 1245145391 - 2² = 1245145387 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1245145397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 88938950 + ... + 88938963.

It is an arithmetic number, because the mean of its divisors is an integer number (355755828).

Almost surely, 2^1245145391 is an apocalyptic number.

1245145391 is a deficient number, since it is larger than the sum of its proper divisors (177877921).

1245145391 is an equidigital number, since it uses as much as digits as its factorization.

1245145391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177877920.

The product of its digits is 21600, while the sum is 35.

The square root of 1245145391 is about 35286.6177325059. The cubic root of 1245145391 is about 1075.8210107395.

The spelling of 1245145391 in words is "one billion, two hundred forty-five million, one hundred forty-five thousand, three hundred ninety-one".