1245440399 has 6 divisors (see below), whose sum is σ = 1448777664. Its totient is φ = 1067520300.

The previous prime is 1245440377. The next prime is 1245440401. The reversal of 1245440399 is 9930445421.

It is a de Polignac number, because none of the positive numbers 2^k-1245440399 is a prime.

It is a super-2 number, since 2×1245440399² = 3102243574922558402, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1245440369) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12708527 + ... + 12708624.

It is an arithmetic number, because the mean of its divisors is an integer number (241462944).

Almost surely, 2^1245440399 is an apocalyptic number.

1245440399 is a deficient number, since it is larger than the sum of its proper divisors (203337265).

1245440399 is an equidigital number, since it uses as much as digits as its factorization.

1245440399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25417165 (or 25417158 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 41.

The square root of 1245440399 is about 35290.7976532127. The cubic root of 1245440399 is about 1075.9059675500.

The spelling of 1245440399 in words is "one billion, two hundred forty-five million, four hundred forty thousand, three hundred ninety-nine".