820633866 has 32 divisors (see below), whose sum is σ = 1775276160. Its totient is φ = 251394624.

The previous prime is 820633837. The next prime is 820633897. The reversal of 820633866 is 668336028.

It is a super-2 number, since 2×820633866² = 1346879884052211912, which contains 22 as substring.

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 15 ways as a sum of consecutive naturals, for example, 5110 + ... + 40833.

It is an arithmetic number, because the mean of its divisors is an integer number (55477380).

Almost surely, 2^820633866 is an apocalyptic number.

820633866 is an abundant number, since it is smaller than the sum of its proper divisors (954642294).

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

820633866 is a wasteful number, since it uses less digits than its factorization.

820633866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46190.

The product of its (nonzero) digits is 248832, while the sum is 42.

The square root of 820633866 is about 28646.7077689566. The cubic root of 820633866 is about 936.2312759453.

The spelling of 820633866 in words is "eight hundred twenty million, six hundred thirty-three thousand, eight hundred sixty-six".