409999999991 has 2 divisors, whose sum is σ = 409999999992. Its totient is φ = 409999999990.

The previous prime is 409999999987. The next prime is 410000000063. The reversal of 409999999991 is 199999999904.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 409999999991 - 2² = 409999999987 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (409999999951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204999999995 + 204999999996.

It is an arithmetic number, because the mean of its divisors is an integer number (204999999996).

Almost surely, 2^409999999991 is an apocalyptic number.

409999999991 is a deficient number, since it is larger than the sum of its proper divisors (1).

409999999991 is an equidigital number, since it uses as much as digits as its factorization.

409999999991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1549681956, while the sum is 86.

The spelling of 409999999991 in words is "four hundred nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-one".