1605431099 has 2 divisors, whose sum is σ = 1605431100. Its totient is φ = 1605431098.

The previous prime is 1605431089. The next prime is 1605431129. The reversal of 1605431099 is 9901345061.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1605431099 - 2⁴ = 1605431083 is a prime.

It is not a weakly prime, because it can be changed into another prime (1605431059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 802715549 + 802715550.

It is an arithmetic number, because the mean of its divisors is an integer number (802715550).

Almost surely, 2^1605431099 is an apocalyptic number.

1605431099 is a deficient number, since it is larger than the sum of its proper divisors (1).

1605431099 is an equidigital number, since it uses as much as digits as its factorization.

1605431099 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 29160, while the sum is 38.

The square root of 1605431099 is about 40067.8312240630. The cubic root of 1605431099 is about 1170.9289865372.

The spelling of 1605431099 in words is "one billion, six hundred five million, four hundred thirty-one thousand, ninety-nine".