18977473 has 2 divisors, whose sum is σ = 18977474. Its totient is φ = 18977472.

The previous prime is 18977471. The next prime is 18977509. The reversal of 18977473 is 37477981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18558864 + 418609 = 4308^2 + 647^2 .

It is a cyclic number.

It is not a de Polignac number, because 18977473 - 2¹ = 18977471 is a prime.

Together with 18977471, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18977471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9488736 + 9488737.

It is an arithmetic number, because the mean of its divisors is an integer number (9488737).

Almost surely, 2^18977473 is an apocalyptic number.

It is an amenable number.

18977473 is a deficient number, since it is larger than the sum of its proper divisors (1).

18977473 is an equidigital number, since it uses as much as digits as its factorization.

18977473 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 296352, while the sum is 46.

The square root of 18977473 is about 4356.3141530427. The cubic root of 18977473 is about 266.7346651246.

The spelling of 18977473 in words is "eighteen million, nine hundred seventy-seven thousand, four hundred seventy-three".