816921412 has 6 divisors (see below), whose sum is σ = 1429612478. Its totient is φ = 408460704.

The previous prime is 816921407. The next prime is 816921421. The reversal of 816921412 is 214129618.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 718990596 + 97930816 = 26814^2 + 9896^2 .

It is an alternating number because its digits alternate between even and odd.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 102115173 + ... + 102115180.

Almost surely, 2^816921412 is an apocalyptic number.

It is an amenable number.

816921412 is a deficient number, since it is larger than the sum of its proper divisors (612691066).

816921412 is a wasteful number, since it uses less digits than its factorization.

816921412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204230357 (or 204230355 counting only the distinct ones).

The product of its digits is 6912, while the sum is 34.

The square root of 816921412 is about 28581.8370998087. The cubic root of 816921412 is about 934.8173404706.

The spelling of 816921412 in words is "eight hundred sixteen million, nine hundred twenty-one thousand, four hundred twelve".