820128782 has 16 divisors (see below), whose sum is σ = 1342870704. Its totient is φ = 372552000.

The previous prime is 820128767. The next prime is 820128847. The reversal of 820128782 is 287821028.

It is a super-2 number, since 2×820128782² = 1345222438129607048, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27032 + ... + 48692.

It is an arithmetic number, because the mean of its divisors is an integer number (83929419).

Almost surely, 2^820128782 is an apocalyptic number.

820128782 is a deficient number, since it is larger than the sum of its proper divisors (522741922).

820128782 is a wasteful number, since it uses less digits than its factorization.

820128782 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23395.

The product of its (nonzero) digits is 28672, while the sum is 38.

The square root of 820128782 is about 28637.8906695308. The cubic root of 820128782 is about 936.0391592147.

The spelling of 820128782 in words is "eight hundred twenty million, one hundred twenty-eight thousand, seven hundred eighty-two".