18921038 has 8 divisors (see below), whose sum is σ = 28427760. Its totient is φ = 9445120.

The previous prime is 18921031. The next prime is 18921043. The reversal of 18921038 is 83012981.

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

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

It is a junction number, because it is equal to n+sod(n) for n = 18920995 and 18921013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18921031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6098 + ... + 8661.

It is an arithmetic number, because the mean of its divisors is an integer number (3553470).

Almost surely, 2^18921038 is an apocalyptic number.

18921038 is a deficient number, since it is larger than the sum of its proper divisors (9506722).

18921038 is a wasteful number, since it uses less digits than its factorization.

18921038 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15402.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 18921038 is about 4349.8319507769. The cubic root of 18921038 is about 266.4699983944.

The spelling of 18921038 in words is "eighteen million, nine hundred twenty-one thousand, thirty-eight".