816169777857 has 40 divisors (see below), whose sum is σ = 1394962141056. Its totient is φ = 465856645248.

The previous prime is 816169777853. The next prime is 816169777859. The reversal of 816169777857 is 758777961618.

It is not a de Polignac number, because 816169777857 - 2² = 816169777853 is a prime.

It is a super-2 number, since 2×816169777857² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (816169777853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 308488 + ... + 1314345.

Almost surely, 2^816169777857 is an apocalyptic number.

It is an amenable number.

816169777857 is a deficient number, since it is larger than the sum of its proper divisors (578792363199).

816169777857 is a wasteful number, since it uses less digits than its factorization.

816169777857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1623739 (or 1623730 counting only the distinct ones).

The product of its digits is 248935680, while the sum is 72.

The spelling of 816169777857 in words is "eight hundred sixteen billion, one hundred sixty-nine million, seven hundred seventy-seven thousand, eight hundred fifty-seven".