820631002 has 4 divisors (see below), whose sum is σ = 1230946506. Its totient is φ = 410315500.

The previous prime is 820630991. The next prime is 820631023. The reversal of 820631002 is 200136028.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 473889361 + 346741641 = 21769^2 + 18621^2 .

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 205157749 + ... + 205157752.

Almost surely, 2^820631002 is an apocalyptic number.

820631002 is a deficient number, since it is larger than the sum of its proper divisors (410315504).

820631002 is a wasteful number, since it uses less digits than its factorization.

820631002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410315503.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 820631002 is about 28646.6577806208. The cubic root of 820631002 is about 936.2301867996.

The spelling of 820631002 in words is "eight hundred twenty million, six hundred thirty-one thousand, two".