820779831 has 16 divisors (see below), whose sum is σ = 1216516320. Its totient is φ = 546940800.

The previous prime is 820779823. The next prime is 820779851. The reversal of 820779831 is 138977028.

It is not a de Polignac number, because 820779831 - 2³ = 820779823 is a prime.

It is a super-2 number, since 2×820779831² = 1347359061952777122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820779811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70201 + ... + 81053.

It is an arithmetic number, because the mean of its divisors is an integer number (76032270).

Almost surely, 2^820779831 is an apocalyptic number.

820779831 is a deficient number, since it is larger than the sum of its proper divisors (395736489).

820779831 is a wasteful number, since it uses less digits than its factorization.

820779831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13663 (or 13657 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 45.

The square root of 820779831 is about 28649.2553306364. The cubic root of 820779831 is about 936.2867813712.

The spelling of 820779831 in words is "eight hundred twenty million, seven hundred seventy-nine thousand, eight hundred thirty-one".