9919781389 has 8 divisors (see below), whose sum is σ = 11829801600. Its totient is φ = 8132988336.

The previous prime is 9919781381. The next prime is 9919781393. The reversal of 9919781389 is 9831879199.

9919781389 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 9919781389 - 2³ = 9919781381 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 9919781389.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9919781381) 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 in 7 ways as a sum of consecutive naturals, for example, 30806614 + ... + 30806935.

It is an arithmetic number, because the mean of its divisors is an integer number (1478725200).

Almost surely, 2^9919781389 is an apocalyptic number.

It is an amenable number.

9919781389 is a deficient number, since it is larger than the sum of its proper divisors (1910020211).

9919781389 is a wasteful number, since it uses less digits than its factorization.

9919781389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61613579.

The product of its digits is 8817984, while the sum is 64.

The square root of 9919781389 is about 99598.0993242341. The cubic root of 9919781389 is about 2148.6583581321.

The spelling of 9919781389 in words is "nine billion, nine hundred nineteen million, seven hundred eighty-one thousand, three hundred eighty-nine".