820004638 has 16 divisors (see below), whose sum is σ = 1279100160. Its totient is φ = 393786400.

The previous prime is 820004623. The next prime is 820004651. The reversal of 820004638 is 836400028.

It is a happy number.

It is a super-2 number, since 2×820004638² = 1344815212683022088, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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, 25933 + ... + 48088.

It is an arithmetic number, because the mean of its divisors is an integer number (79943760).

Almost surely, 2^820004638 is an apocalyptic number.

820004638 is a deficient number, since it is larger than the sum of its proper divisors (459095522).

820004638 is a wasteful number, since it uses less digits than its factorization.

820004638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74243.

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 820004638 is about 28635.7231094310. The cubic root of 820004638 is about 935.9919269947.

The spelling of 820004638 in words is "eight hundred twenty million, four thousand, six hundred thirty-eight".