1389745821 has 8 divisors (see below), whose sum is σ = 1858245120. Its totient is φ = 923871872.

The previous prime is 1389745793. The next prime is 1389745829. The reversal of 1389745821 is 1285479831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1389745821 - 2¹⁷ = 1389614749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1389745829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 655101 + ... + 657218.

It is an arithmetic number, because the mean of its divisors is an integer number (232280640).

Almost surely, 2^1389745821 is an apocalyptic number.

It is an amenable number.

1389745821 is a deficient number, since it is larger than the sum of its proper divisors (468499299).

1389745821 is a wasteful number, since it uses less digits than its factorization.

1389745821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1312675.

The product of its digits is 483840, while the sum is 48.

The square root of 1389745821 is about 37279.2948028795. The cubic root of 1389745821 is about 1115.9509997306.

The spelling of 1389745821 in words is "one billion, three hundred eighty-nine million, seven hundred forty-five thousand, eight hundred twenty-one".