1816247491 has 2 divisors, whose sum is σ = 1816247492. Its totient is φ = 1816247490.

The previous prime is 1816247471. The next prime is 1816247533. The reversal of 1816247491 is 1947426181.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1816247491 - 2⁹ = 1816246979 is a prime.

It is not a weakly prime, because it can be changed into another prime (1816247471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 908123745 + 908123746.

It is an arithmetic number, because the mean of its divisors is an integer number (908123746).

Almost surely, 2^1816247491 is an apocalyptic number.

1816247491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1816247491 is an equidigital number, since it uses as much as digits as its factorization.

1816247491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96768, while the sum is 43.

The square root of 1816247491 is about 42617.4552384349. The cubic root of 1816247491 is about 1220.0894611008.

The spelling of 1816247491 in words is "one billion, eight hundred sixteen million, two hundred forty-seven thousand, four hundred ninety-one".