102820 has 24 divisors (see below), whose sum is σ = 222264. Its totient is φ = 39936.

The previous prime is 102811. The next prime is 102829. The reversal of 102820 is 28201.

It is an interprime number because it is at equal distance from previous prime (102811) and next prime (102829).

It can be written as a sum of positive squares in 4 ways, for example, as 16384 + 86436 = 128^2 + 294^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 102820.

It is not an unprimeable number, because it can be changed into a prime (102829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1012 + ... + 1108.

It is an arithmetic number, because the mean of its divisors is an integer number (9261).

2¹⁰²⁸²⁰ is an apocalyptic number.

102820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

102820 is an abundant number, since it is smaller than the sum of its proper divisors (119444).

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

102820 is a wasteful number, since it uses less digits than its factorization.

102820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159 (or 157 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 102820 is about 320.6555784639. The cubic root of 102820 is about 46.8481594489.

The spelling of 102820 in words is "one hundred two thousand, eight hundred twenty".