18913457 has 2 divisors, whose sum is σ = 18913458. Its totient is φ = 18913456.

The previous prime is 18913403. The next prime is 18913471. The reversal of 18913457 is 75431981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13719616 + 5193841 = 3704^2 + 2279^2 .

It is an emirp because it is prime and its reverse (75431981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18913457 - 2⁸ = 18913201 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 18913457.

It is not a weakly prime, because it can be changed into another prime (18913487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9456728 + 9456729.

It is an arithmetic number, because the mean of its divisors is an integer number (9456729).

Almost surely, 2^18913457 is an apocalyptic number.

It is an amenable number.

18913457 is a deficient number, since it is larger than the sum of its proper divisors (1).

18913457 is an equidigital number, since it uses as much as digits as its factorization.

18913457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 38.

The square root of 18913457 is about 4348.9604504985. The cubic root of 18913457 is about 266.4344052289.

The spelling of 18913457 in words is "eighteen million, nine hundred thirteen thousand, four hundred fifty-seven".