816621838 has 8 divisors (see below), whose sum is σ = 1229591088. Its totient is φ = 406758144.

The previous prime is 816621833. The next prime is 816621847. The reversal of 816621838 is 838126618.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 816621794 and 816621803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816621833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 775731 + ... + 776782.

It is an arithmetic number, because the mean of its divisors is an integer number (153698886).

Almost surely, 2^816621838 is an apocalyptic number.

816621838 is a deficient number, since it is larger than the sum of its proper divisors (412969250).

816621838 is a wasteful number, since it uses less digits than its factorization.

816621838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1552778.

The product of its digits is 110592, while the sum is 43.

The square root of 816621838 is about 28576.5959834267. The cubic root of 816621838 is about 934.7030572585.

The spelling of 816621838 in words is "eight hundred sixteen million, six hundred twenty-one thousand, eight hundred thirty-eight".