210821473 has 12 divisors (see below), whose sum is σ = 232184448. Its totient is φ = 191034360.

The previous prime is 210821459. The next prime is 210821489. The reversal of 210821473 is 374128012.

It is a de Polignac number, because none of the positive numbers 2^k-210821473 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210821423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4393 + ... + 20998.

It is an arithmetic number, because the mean of its divisors is an integer number (19348704).

Almost surely, 2^210821473 is an apocalyptic number.

210821473 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

210821473 is a deficient number, since it is larger than the sum of its proper divisors (21362975).

210821473 is a wasteful number, since it uses less digits than its factorization.

210821473 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25452 (or 25433 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 210821473 is about 14519.6925931646. The cubic root of 210821473 is about 595.1662299476.

Adding to 210821473 its reverse (374128012), we get a palindrome (584949485).

The spelling of 210821473 in words is "two hundred ten million, eight hundred twenty-one thousand, four hundred seventy-three".