18929989 has 8 divisors (see below), whose sum is σ = 21272832. Its totient is φ = 16713840.

The previous prime is 18929983. The next prime is 18930013. The reversal of 18929989 is 98992981.

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

It is not a de Polignac number, because 18929989 - 2¹⁹ = 18405701 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18929983) 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, 31357 + ... + 31954.

It is an arithmetic number, because the mean of its divisors is an integer number (2659104).

Almost surely, 2^18929989 is an apocalyptic number.

It is an amenable number.

18929989 is a deficient number, since it is larger than the sum of its proper divisors (2342843).

18929989 is a wasteful number, since it uses less digits than its factorization.

18929989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63347.

The product of its digits is 839808, while the sum is 55.

The square root of 18929989 is about 4350.8607194439. The cubic root of 18929989 is about 266.5120115393.

It can be divided in two parts, 1892 and 9989, that added together give a square (11881 = 109²).

The spelling of 18929989 in words is "eighteen million, nine hundred twenty-nine thousand, nine hundred eighty-nine".