820631001 has 4 divisors (see below), whose sum is σ = 1094174672. Its totient is φ = 547087332.

The previous prime is 820630991. The next prime is 820631023. The reversal of 820631001 is 100136028.

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 not a de Polignac number, because 820631001 - 2⁵ = 820630969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (820631051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136771831 + ... + 136771836.

It is an arithmetic number, because the mean of its divisors is an integer number (273543668).

Almost surely, 2^820631001 is an apocalyptic number.

It is an amenable number.

820631001 is a deficient number, since it is larger than the sum of its proper divisors (273543671).

820631001 is a wasteful number, since it uses less digits than its factorization.

820631001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273543670.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 820631001 is about 28646.6577631667. The cubic root of 820631001 is about 936.2301864193.

Adding to 820631001 its reverse (100136028), we get a palindrome (920767029).

The spelling of 820631001 in words is "eight hundred twenty million, six hundred thirty-one thousand, one".