16403907491 has 2 divisors, whose sum is σ = 16403907492. Its totient is φ = 16403907490.

The previous prime is 16403907383. The next prime is 16403907551. The reversal of 16403907491 is 19470930461.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16403907491 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (16403907991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8201953745 + 8201953746.

It is an arithmetic number, because the mean of its divisors is an integer number (8201953746).

Almost surely, 2^16403907491 is an apocalyptic number.

16403907491 is a deficient number, since it is larger than the sum of its proper divisors (1).

16403907491 is an equidigital number, since it uses as much as digits as its factorization.

16403907491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 163296, while the sum is 44.

The spelling of 16403907491 in words is "sixteen billion, four hundred three million, nine hundred seven thousand, four hundred ninety-one".