1661429999 has 2 divisors, whose sum is σ = 1661430000. Its totient is φ = 1661429998.

The previous prime is 1661429971. The next prime is 1661430011. The reversal of 1661429999 is 9999241661.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1661429999 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1661429929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830714999 + 830715000.

It is an arithmetic number, because the mean of its divisors is an integer number (830715000).

Almost surely, 2^1661429999 is an apocalyptic number.

1661429999 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661429999 is an equidigital number, since it uses as much as digits as its factorization.

1661429999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1889568, while the sum is 56.

The square root of 1661429999 is about 40760.6427697111. The cubic root of 1661429999 is about 1184.3880474833.

The spelling of 1661429999 in words is "one billion, six hundred sixty-one million, four hundred twenty-nine thousand, nine hundred ninety-nine".