1389884921 has 4 divisors (see below), whose sum is σ = 1393110144. Its totient is φ = 1386659700.

The previous prime is 1389884911. The next prime is 1389884957. The reversal of 1389884921 is 1294889831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1389884921 - 2²² = 1385690617 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1389884911) 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, 1611965 + ... + 1612826.

It is an arithmetic number, because the mean of its divisors is an integer number (348277536).

Almost surely, 2^1389884921 is an apocalyptic number.

It is an amenable number.

1389884921 is a deficient number, since it is larger than the sum of its proper divisors (3225223).

1389884921 is an equidigital number, since it uses as much as digits as its factorization.

1389884921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3225222.

The product of its digits is 995328, while the sum is 53.

The square root of 1389884921 is about 37281.1604030776. The cubic root of 1389884921 is about 1115.9882304249.

The spelling of 1389884921 in words is "one billion, three hundred eighty-nine million, eight hundred eighty-four thousand, nine hundred twenty-one".