18918451 has 2 divisors, whose sum is σ = 18918452. Its totient is φ = 18918450.

The previous prime is 18918437. The next prime is 18918457. The reversal of 18918451 is 15481981.

It is a strong prime.

It is an emirp because it is prime and its reverse (15481981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18918451 - 2¹³ = 18910259 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 18918451.

It is not a weakly prime, because it can be changed into another prime (18918457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9459225 + 9459226.

It is an arithmetic number, because the mean of its divisors is an integer number (9459226).

Almost surely, 2^18918451 is an apocalyptic number.

18918451 is a deficient number, since it is larger than the sum of its proper divisors (1).

18918451 is an equidigital number, since it uses as much as digits as its factorization.

18918451 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11520, while the sum is 37.

The square root of 18918451 is about 4349.5345728020. The cubic root of 18918451 is about 266.4578533717.

The spelling of 18918451 in words is "eighteen million, nine hundred eighteen thousand, four hundred fifty-one".