210021008 has 20 divisors (see below), whose sum is σ = 407466108. Its totient is φ = 104868480.

The previous prime is 210020989. The next prime is 210021047. The reversal of 210021008 is 800120012.

It can be written as a sum of positive squares in 2 ways, for example, as 117245584 + 92775424 = 10828^2 + 9632^2 .

It is a junction number, because it is equal to n+sod(n) for n = 210020983 and 210021001.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3878 + ... + 20858.

Almost surely, 2^210021008 is an apocalyptic number.

It is an amenable number.

210021008 is a deficient number, since it is larger than the sum of its proper divisors (197445100).

210021008 is a wasteful number, since it uses less digits than its factorization.

210021008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17762 (or 17756 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 210021008 is about 14492.1015729259. The cubic root of 210021008 is about 594.4120152364.

The spelling of 210021008 in words is "two hundred ten million, twenty-one thousand, eight".