18978253 has 8 divisors (see below), whose sum is σ = 21823808. Its totient is φ = 16166304.

The previous prime is 18978251. The next prime is 18978257. The reversal of 18978253 is 35287981.

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

It is not a de Polignac number, because 18978253 - 2¹ = 18978251 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 (18978251) 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, 7176 + ... + 9457.

It is an arithmetic number, because the mean of its divisors is an integer number (2727976).

Almost surely, 2^18978253 is an apocalyptic number.

It is an amenable number.

18978253 is a deficient number, since it is larger than the sum of its proper divisors (2845555).

18978253 is a wasteful number, since it uses less digits than its factorization.

18978253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16803.

The product of its digits is 120960, while the sum is 43.

The square root of 18978253 is about 4356.4036773467. The cubic root of 18978253 is about 266.7383194606.

The spelling of 18978253 in words is "eighteen million, nine hundred seventy-eight thousand, two hundred fifty-three".