18968551 has 4 divisors (see below), whose sum is σ = 21678352. Its totient is φ = 16258752.

The previous prime is 18968513. The next prime is 18968561. The reversal of 18968551 is 15586981.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18968551 - 2⁷ = 18968423 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18968498 and 18968507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18968561) 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, 1354890 + ... + 1354903.

It is an arithmetic number, because the mean of its divisors is an integer number (5419588).

Almost surely, 2^18968551 is an apocalyptic number.

18968551 is a deficient number, since it is larger than the sum of its proper divisors (2709801).

18968551 is an equidigital number, since it uses as much as digits as its factorization.

18968551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2709800.

The product of its digits is 86400, while the sum is 43.

The square root of 18968551 is about 4355.2900018254. The cubic root of 18968551 is about 266.6928580177.

The spelling of 18968551 in words is "eighteen million, nine hundred sixty-eight thousand, five hundred fifty-one".