1389978465 has 16 divisors (see below), whose sum is σ = 2295707136. Its totient is φ = 717408000.

The previous prime is 1389978437. The next prime is 1389978467. The reversal of 1389978465 is 5648799831.

It is not a de Polignac number, because 1389978465 - 2¹⁰ = 1389977441 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1389978399 and 1389978408.

It is not an unprimeable number, because it can be changed into a prime (1389978467) 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, 1494136 + ... + 1495065.

It is an arithmetic number, because the mean of its divisors is an integer number (143481696).

Almost surely, 2^1389978465 is an apocalyptic number.

1389978465 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1389978465 is a deficient number, since it is larger than the sum of its proper divisors (905728671).

1389978465 is a wasteful number, since it uses less digits than its factorization.

1389978465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2989240.

The product of its digits is 13063680, while the sum is 60.

The square root of 1389978465 is about 37282.4149566522. The cubic root of 1389978465 is about 1116.0132664691.

The spelling of 1389978465 in words is "one billion, three hundred eighty-nine million, nine hundred seventy-eight thousand, four hundred sixty-five".