816478388 has 12 divisors (see below), whose sum is σ = 1558731552. Its totient is φ = 371126520.

The previous prime is 816478381. The next prime is 816478417. The reversal of 816478388 is 883874618.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816478381) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9278120 + ... + 9278207.

It is an arithmetic number, because the mean of its divisors is an integer number (129894296).

Almost surely, 2^816478388 is an apocalyptic number.

It is an amenable number.

816478388 is a deficient number, since it is larger than the sum of its proper divisors (742253164).

816478388 is a wasteful number, since it uses less digits than its factorization.

816478388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18556342 (or 18556340 counting only the distinct ones).

The product of its digits is 2064384, while the sum is 53.

The square root of 816478388 is about 28574.0859521350. The cubic root of 816478388 is about 934.6483232313.

The spelling of 816478388 in words is "eight hundred sixteen million, four hundred seventy-eight thousand, three hundred eighty-eight".