1378742399 has 4 divisors (see below), whose sum is σ = 1385886336. Its totient is φ = 1371598464.

The previous prime is 1378742377. The next prime is 1378742413. The reversal of 1378742399 is 9932478731.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9932478731 = 7 ⋅1418925533.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1378742399 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1378742399.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1378742899) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3571679 + ... + 3572064.

It is an arithmetic number, because the mean of its divisors is an integer number (346471584).

Almost surely, 2^1378742399 is an apocalyptic number.

1378742399 is a deficient number, since it is larger than the sum of its proper divisors (7143937).

1378742399 is an equidigital number, since it uses as much as digits as its factorization.

1378742399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7143936.

The product of its digits is 2286144, while the sum is 53.

The square root of 1378742399 is about 37131.4206434389. The cubic root of 1378742399 is about 1112.9979824020.

The spelling of 1378742399 in words is "one billion, three hundred seventy-eight million, seven hundred forty-two thousand, three hundred ninety-nine".