18661429 has 2 divisors, whose sum is σ = 18661430. Its totient is φ = 18661428.

The previous prime is 18661417. The next prime is 18661457. The reversal of 18661429 is 92416681.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14364100 + 4297329 = 3790^2 + 2073^2 .

It is a cyclic number.

It is not a de Polignac number, because 18661429 - 2¹⁵ = 18628661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18661469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9330714 + 9330715.

It is an arithmetic number, because the mean of its divisors is an integer number (9330715).

Almost surely, 2^18661429 is an apocalyptic number.

It is an amenable number.

18661429 is a deficient number, since it is larger than the sum of its proper divisors (1).

18661429 is an equidigital number, since it uses as much as digits as its factorization.

18661429 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 37.

The square root of 18661429 is about 4319.8876142789. The cubic root of 18661429 is about 265.2456675206.

The spelling of 18661429 in words is "eighteen million, six hundred sixty-one thousand, four hundred twenty-nine".