18973553 has 2 divisors, whose sum is σ = 18973554. Its totient is φ = 18973552.

The previous prime is 18973531. The next prime is 18973573. The reversal of 18973553 is 35537981.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10975969 + 7997584 = 3313^2 + 2828^2 .

It is a cyclic number.

It is not a de Polignac number, because 18973553 - 2¹⁰ = 18972529 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18973553.

It is not a weakly prime, because it can be changed into another prime (18973573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9486776 + 9486777.

It is an arithmetic number, because the mean of its divisors is an integer number (9486777).

Almost surely, 2^18973553 is an apocalyptic number.

It is an amenable number.

18973553 is a deficient number, since it is larger than the sum of its proper divisors (1).

18973553 is an equidigital number, since it uses as much as digits as its factorization.

18973553 is an evil number, because the sum of its binary digits is even.

The product of its digits is 113400, while the sum is 41.

The square root of 18973553 is about 4355.8642081681. The cubic root of 18973553 is about 266.7162982274.

The spelling of 18973553 in words is "eighteen million, nine hundred seventy-three thousand, five hundred fifty-three".