816503521770551 has 16 divisors (see below), whose sum is σ = 844221799215360. Its totient is φ = 788872353776640.

The previous prime is 816503521770533. The next prime is 816503521770583. The reversal of 816503521770551 is 155077125305618.

It is a cyclic number.

It is not a de Polignac number, because 816503521770551 - 2²² = 816503517576247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816503521770851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47391245 + ... + 62281113.

It is an arithmetic number, because the mean of its divisors is an integer number (52763862450960).

Almost surely, 2^{816503521770551} is an apocalyptic number.

816503521770551 is a deficient number, since it is larger than the sum of its proper divisors (27718277444809).

816503521770551 is a wasteful number, since it uses less digits than its factorization.

816503521770551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14892794.

The product of its (nonzero) digits is 8820000, while the sum is 56.

The spelling of 816503521770551 in words is "eight hundred sixteen trillion, five hundred three billion, five hundred twenty-one million, seven hundred seventy thousand, five hundred fifty-one".