820669520 has 40 divisors (see below), whose sum is σ = 2081518560. Its totient is φ = 298424960.

The previous prime is 820669517. The next prime is 820669529. The reversal of 820669520 is 25966028.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×820669520² = 1346996922114060800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820669529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 465410 + ... + 467169.

It is an arithmetic number, because the mean of its divisors is an integer number (52037964).

Almost surely, 2^820669520 is an apocalyptic number.

820669520 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

820669520 is an abundant number, since it is smaller than the sum of its proper divisors (1260849040).

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

820669520 is a wasteful number, since it uses less digits than its factorization.

820669520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 932603 (or 932597 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 38.

The square root of 820669520 is about 28647.3300675648. The cubic root of 820669520 is about 936.2448345321.

The spelling of 820669520 in words is "eight hundred twenty million, six hundred sixty-nine thousand, five hundred twenty".