821768130 has 24 divisors (see below), whose sum is σ = 2136597372. Its totient is φ = 219138144.

The previous prime is 821768071. The next prime is 821768131. The reversal of 821768130 is 31867128.

It can be written as a sum of positive squares in 2 ways, for example, as 696484881 + 125283249 = 26391^2 + 11193^2 .

It is not an unprimeable number, because it can be changed into a prime (821768131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4565289 + ... + 4565468.

Almost surely, 2^821768130 is an apocalyptic number.

821768130 is an abundant number, since it is smaller than the sum of its proper divisors (1314829242).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

821768130 is a wasteful number, since it uses less digits than its factorization.

821768130 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9130770 (or 9130767 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 821768130 is about 28666.4983909790. The cubic root of 821768130 is about 936.6624241874.

The spelling of 821768130 in words is "eight hundred twenty-one million, seven hundred sixty-eight thousand, one hundred thirty".