1389395621 has 16 divisors (see below), whose sum is σ = 1443557376. Its totient is φ = 1336196736.

The previous prime is 1389395593. The next prime is 1389395629. The reversal of 1389395621 is 1265939831.

It is a cyclic number.

It is not a de Polignac number, because 1389395621 - 2¹⁰ = 1389394597 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 (1389395629) 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, 2147120 + ... + 2147766.

It is an arithmetic number, because the mean of its divisors is an integer number (90222336).

Almost surely, 2^1389395621 is an apocalyptic number.

It is an amenable number.

1389395621 is a deficient number, since it is larger than the sum of its proper divisors (54161755).

1389395621 is a wasteful number, since it uses less digits than its factorization.

1389395621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1268.

The product of its digits is 349920, while the sum is 47.

The square root of 1389395621 is about 37274.5975296850. The cubic root of 1389395621 is about 1115.8572562405.

The spelling of 1389395621 in words is "one billion, three hundred eighty-nine million, three hundred ninety-five thousand, six hundred twenty-one".