820655505 has 24 divisors (see below), whose sum is σ = 1497337920. Its totient is φ = 414646560.

The previous prime is 820655491. The next prime is 820655531. The reversal of 820655505 is 505556028.

It is not a de Polignac number, because 820655505 - 2⁷ = 820655377 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 820655505.

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, 479061 + ... + 480770.

It is an arithmetic number, because the mean of its divisors is an integer number (62389080).

Almost surely, 2^820655505 is an apocalyptic number.

It is an amenable number.

820655505 is a deficient number, since it is larger than the sum of its proper divisors (676682415).

820655505 is a wasteful number, since it uses less digits than its factorization.

820655505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 959861 (or 959858 counting only the distinct ones).

The product of its (nonzero) digits is 60000, while the sum is 36.

The square root of 820655505 is about 28647.0854538468. The cubic root of 820655505 is about 936.2395049219.

The spelling of 820655505 in words is "eight hundred twenty million, six hundred fifty-five thousand, five hundred five".