1389845404921 has 2 divisors, whose sum is σ = 1389845404922. Its totient is φ = 1389845404920.

The previous prime is 1389845404879. The next prime is 1389845404967. The reversal of 1389845404921 is 1294045489831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1233456793321 + 156388611600 = 1110611^2 + 395460^2 .

It is a cyclic number.

It is not a de Polignac number, because 1389845404921 - 2³⁷ = 1252406451449 is a prime.

It is not a weakly prime, because it can be changed into another prime (1389845404991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 694922702460 + 694922702461.

It is an arithmetic number, because the mean of its divisors is an integer number (694922702461).

Almost surely, 2^{1389845404921} is an apocalyptic number.

It is an amenable number.

1389845404921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1389845404921 is an equidigital number, since it uses as much as digits as its factorization.

1389845404921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9953280, while the sum is 58.

The spelling of 1389845404921 in words is "one trillion, three hundred eighty-nine billion, eight hundred forty-five million, four hundred four thousand, nine hundred twenty-one".