816440012551 has 2 divisors, whose sum is σ = 816440012552. Its totient is φ = 816440012550.

The previous prime is 816440012539. The next prime is 816440012611. The reversal of 816440012551 is 155210044618.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 816440012551 - 2⁵ = 816440012519 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 816440012551.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (816440012851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 408220006275 + 408220006276.

It is an arithmetic number, because the mean of its divisors is an integer number (408220006276).

Almost surely, 2^816440012551 is an apocalyptic number.

816440012551 is a deficient number, since it is larger than the sum of its proper divisors (1).

816440012551 is an equidigital number, since it uses as much as digits as its factorization.

816440012551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38400, while the sum is 37.

The spelling of 816440012551 in words is "eight hundred sixteen billion, four hundred forty million, twelve thousand, five hundred fifty-one".