820786428 has 72 divisors (see below), whose sum is σ = 2586729600. Its totient is φ = 213190560.

The previous prime is 820786409. The next prime is 820786433. The reversal of 820786428 is 824687028.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 145278 + ... + 150821.

It is an arithmetic number, because the mean of its divisors is an integer number (35926800).

Almost surely, 2^820786428 is an apocalyptic number.

It is an amenable number.

820786428 is an abundant number, since it is smaller than the sum of its proper divisors (1765943172).

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

820786428 is a wasteful number, since it uses less digits than its factorization.

820786428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296127 (or 296122 counting only the distinct ones).

The product of its (nonzero) digits is 344064, while the sum is 45.

The square root of 820786428 is about 28649.3704642877. The cubic root of 820786428 is about 936.2892898260.

The spelling of 820786428 in words is "eight hundred twenty million, seven hundred eighty-six thousand, four hundred twenty-eight".