809820212 has 6 divisors (see below), whose sum is σ = 1417185378. Its totient is φ = 404910104.

The previous prime is 809820181. The next prime is 809820239. The reversal of 809820212 is 212028908.

It can be written as a sum of positive squares in only one way, i.e., 809630116 + 190096 = 28454^2 + 436^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101227523 + ... + 101227530.

It is an arithmetic number, because the mean of its divisors is an integer number (236197563).

Almost surely, 2^809820212 is an apocalyptic number.

It is an amenable number.

809820212 is a deficient number, since it is larger than the sum of its proper divisors (607365166).

809820212 is a wasteful number, since it uses less digits than its factorization.

809820212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202455057 (or 202455055 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 809820212 is about 28457.3402130276. The cubic root of 809820212 is about 932.1007783966.

The spelling of 809820212 in words is "eight hundred nine million, eight hundred twenty thousand, two hundred twelve".