210145421 has 2 divisors, whose sum is σ = 210145422. Its totient is φ = 210145420.

The previous prime is 210145417. The next prime is 210145423. The reversal of 210145421 is 124541012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 186622921 + 23522500 = 13661^2 + 4850^2 .

It is a cyclic number.

It is not a de Polignac number, because 210145421 - 2² = 210145417 is a prime.

It is a super-2 number, since 2×210145421² = 88322195934534482, which contains 22 as substring.

Together with 210145423, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 210145393 and 210145402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (210145423) 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 as a sum of consecutive naturals, namely, 105072710 + 105072711.

It is an arithmetic number, because the mean of its divisors is an integer number (105072711).

Almost surely, 2^210145421 is an apocalyptic number.

It is an amenable number.

210145421 is a deficient number, since it is larger than the sum of its proper divisors (1).

210145421 is an equidigital number, since it uses as much as digits as its factorization.

210145421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 210145421 is about 14496.3933790443. The cubic root of 210145421 is about 594.5293653764.

Adding to 210145421 its reverse (124541012), we get a palindrome (334686433).

The spelling of 210145421 in words is "two hundred ten million, one hundred forty-five thousand, four hundred twenty-one".