18439457 has 2 divisors, whose sum is σ = 18439458. Its totient is φ = 18439456.

The previous prime is 18439439. The next prime is 18439471. The reversal of 18439457 is 75493481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16654561 + 1784896 = 4081^2 + 1336^2 .

It is a cyclic number.

It is not a de Polignac number, because 18439457 - 2¹⁴ = 18423073 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18439427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9219728 + 9219729.

It is an arithmetic number, because the mean of its divisors is an integer number (9219729).

Almost surely, 2^18439457 is an apocalyptic number.

It is an amenable number.

18439457 is a deficient number, since it is larger than the sum of its proper divisors (1).

18439457 is an equidigital number, since it uses as much as digits as its factorization.

18439457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120960, while the sum is 41.

The square root of 18439457 is about 4294.1188851731. The cubic root of 18439457 is about 264.1897978973.

The spelling of 18439457 in words is "eighteen million, four hundred thirty-nine thousand, four hundred fifty-seven".