210421139 has 4 divisors (see below), whose sum is σ = 210570024. Its totient is φ = 210272256.

The previous prime is 210421073. The next prime is 210421151. The reversal of 210421139 is 931124012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-210421139 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (210421039) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 72302 + ... + 75155.

It is an arithmetic number, because the mean of its divisors is an integer number (52642506).

Almost surely, 2^210421139 is an apocalyptic number.

210421139 is a deficient number, since it is larger than the sum of its proper divisors (148885).

210421139 is a wasteful number, since it uses less digits than its factorization.

210421139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148884.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 210421139 is about 14505.9001444240. The cubic root of 210421139 is about 594.7892660496.

The spelling of 210421139 in words is "two hundred ten million, four hundred twenty-one thousand, one hundred thirty-nine".