816949979 has 6 divisors (see below), whose sum is σ = 823449564. Its totient is φ = 810501300.

The previous prime is 816949951. The next prime is 816949999. The reversal of 816949979 is 979949618.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-816949979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (816949919) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9197 + ... + 41454.

It is an arithmetic number, because the mean of its divisors is an integer number (137241594).

Almost surely, 2^816949979 is an apocalyptic number.

816949979 is a deficient number, since it is larger than the sum of its proper divisors (6499585).

816949979 is an equidigital number, since it uses as much as digits as its factorization.

816949979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50905 (or 50778 counting only the distinct ones).

The product of its digits is 8817984, while the sum is 62.

The square root of 816949979 is about 28582.3368358852. The cubic root of 816949979 is about 934.8282369148.

The spelling of 816949979 in words is "eight hundred sixteen million, nine hundred forty-nine thousand, nine hundred seventy-nine".