993921389 has 2 divisors, whose sum is σ = 993921390. Its totient is φ = 993921388.

The previous prime is 993921367. The next prime is 993921419. The reversal of 993921389 is 983129399.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 991620100 + 2301289 = 31490^2 + 1517^2 .

It is a cyclic number.

It is not a de Polignac number, because 993921389 - 2²⁸ = 725485933 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 993921389.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (993921289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 496960694 + 496960695.

It is an arithmetic number, because the mean of its divisors is an integer number (496960695).

Almost surely, 2^993921389 is an apocalyptic number.

It is an amenable number.

993921389 is a deficient number, since it is larger than the sum of its proper divisors (1).

993921389 is an equidigital number, since it uses as much as digits as its factorization.

993921389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 944784, while the sum is 53.

The square root of 993921389 is about 31526.5188214620. The cubic root of 993921389 is about 997.9696769113.

The spelling of 993921389 in words is "nine hundred ninety-three million, nine hundred twenty-one thousand, three hundred eighty-nine".