821699990 has 16 divisors (see below), whose sum is σ = 1482262848. Its totient is φ = 327968256.

The previous prime is 821699987. The next prime is 821700017. The reversal of 821699990 is 99996128.

821699990 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84107 + ... + 93366.

It is an arithmetic number, because the mean of its divisors is an integer number (92641428).

Almost surely, 2^821699990 is an apocalyptic number.

821699990 is a deficient number, since it is larger than the sum of its proper divisors (660562858).

821699990 is a wasteful number, since it uses less digits than its factorization.

821699990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177943.

The product of its (nonzero) digits is 629856, while the sum is 53.

The square root of 821699990 is about 28665.3098709922. The cubic root of 821699990 is about 936.6365345074.

The spelling of 821699990 in words is "eight hundred twenty-one million, six hundred ninety-nine thousand, nine hundred ninety".