18929872 has 20 divisors (see below), whose sum is σ = 39498340. Its totient is φ = 8736768.

The previous prime is 18929863. The next prime is 18929879. The reversal of 18929872 is 27892981.

It can be written as a sum of positive squares in 2 ways, for example, as 3594816 + 15335056 = 1896^2 + 3916^2 .

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18929879) 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, 45297 + ... + 45712.

It is an arithmetic number, because the mean of its divisors is an integer number (1974917).

Almost surely, 2^18929872 is an apocalyptic number.

It is an amenable number.

18929872 is an abundant number, since it is smaller than the sum of its proper divisors (20568468).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18929872 is a wasteful number, since it uses less digits than its factorization.

18929872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91030 (or 91024 counting only the distinct ones).

The product of its digits is 145152, while the sum is 46.

The square root of 18929872 is about 4350.8472738077. The cubic root of 18929872 is about 266.5114624640.

The spelling of 18929872 in words is "eighteen million, nine hundred twenty-nine thousand, eight hundred seventy-two".