820101 has 4 divisors (see below), whose sum is σ = 1093472. Its totient is φ = 546732.

The previous prime is 820093. The next prime is 820109. The reversal of 820101 is 101028.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (820093) and next prime (820109).

It is not a de Polignac number, because 820101 - 2³ = 820093 is a prime.

It is a D-number.

It is a Duffinian number.

820101 is a modest number, since divided by 101 gives 82 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820109) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136681 + ... + 136686.

It is an arithmetic number, because the mean of its divisors is an integer number (273368).

2⁸²⁰¹⁰¹ is an apocalyptic number.

It is an amenable number.

820101 is a deficient number, since it is larger than the sum of its proper divisors (273371).

820101 is a wasteful number, since it uses less digits than its factorization.

820101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273370.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 820101 is about 905.5942800173. The cubic root of 820101 is about 93.6028589601.

Adding to 820101 its reverse (101028), we get a palindrome (921129).

The spelling of 820101 in words is "eight hundred twenty thousand, one hundred one".