210005421 has 16 divisors (see below), whose sum is σ = 286978560. Its totient is φ = 136528560.

The previous prime is 210005417. The next prime is 210005429. The reversal of 210005421 is 124500012.

210005421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 210005421 - 2² = 210005417 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 210005421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210005429) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 132210 + ... + 133788.

It is an arithmetic number, because the mean of its divisors is an integer number (17936160).

Almost surely, 2^210005421 is an apocalyptic number.

It is an amenable number.

210005421 is a deficient number, since it is larger than the sum of its proper divisors (76973139).

210005421 is a wasteful number, since it uses less digits than its factorization.

210005421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2656.

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 210005421 is about 14491.5637872522. The cubic root of 210005421 is about 594.3973098356.

Adding to 210005421 its reverse (124500012), we get a palindrome (334505433).

The spelling of 210005421 in words is "two hundred ten million, five thousand, four hundred twenty-one".