1378838391509 has 16 divisors (see below), whose sum is σ = 1533125864448. Its totient is φ = 1233400726272.

The previous prime is 1378838391493. The next prime is 1378838391523. The reversal of 1378838391509 is 9051938388731.

It is a cyclic number.

It is not a de Polignac number, because 1378838391509 - 2⁴ = 1378838391493 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1378838391529) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11169317 + ... + 11292090.

It is an arithmetic number, because the mean of its divisors is an integer number (95820366528).

Almost surely, 2^{1378838391509} is an apocalyptic number.

It is an amenable number.

1378838391509 is a deficient number, since it is larger than the sum of its proper divisors (154287472939).

1378838391509 is a wasteful number, since it uses less digits than its factorization.

1378838391509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22461604.

The product of its (nonzero) digits is 39191040, while the sum is 65.

The spelling of 1378838391509 in words is "one trillion, three hundred seventy-eight billion, eight hundred thirty-eight million, three hundred ninety-one thousand, five hundred nine".