820339780 has 24 divisors (see below), whose sum is σ = 1855230552. Its totient is φ = 302894592.

The previous prime is 820339769. The next prime is 820339799. The reversal of 820339780 is 87933028.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 33200644 + 787139136 = 5762^2 + 28056^2 .

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, 1577317 + ... + 1577836.

It is an arithmetic number, because the mean of its divisors is an integer number (77301273).

Almost surely, 2^820339780 is an apocalyptic number.

It is an amenable number.

820339780 is an abundant number, since it is smaller than the sum of its proper divisors (1034890772).

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

820339780 is a wasteful number, since it uses less digits than its factorization.

820339780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3155175 (or 3155173 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 820339780 is about 28641.5743282383. The cubic root of 820339780 is about 936.1194252493.

The spelling of 820339780 in words is "eight hundred twenty million, three hundred thirty-nine thousand, seven hundred eighty".