816511987583 has 2 divisors, whose sum is σ = 816511987584. Its totient is φ = 816511987582.

The previous prime is 816511987537. The next prime is 816511987651. The reversal of 816511987583 is 385789115618.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 816511987583 - 2⁸ = 816511987327 is a prime.

It is a super-2 number, since 2×816511987583² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (816511981583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 408255993791 + 408255993792.

It is an arithmetic number, because the mean of its divisors is an integer number (408255993792).

Almost surely, 2^816511987583 is an apocalyptic number.

816511987583 is a deficient number, since it is larger than the sum of its proper divisors (1).

816511987583 is an equidigital number, since it uses as much as digits as its factorization.

816511987583 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14515200, while the sum is 62.

The spelling of 816511987583 in words is "eight hundred sixteen billion, five hundred eleven million, nine hundred eighty-seven thousand, five hundred eighty-three".