210121421 has 8 divisors (see below), whose sum is σ = 213025080. Its totient is φ = 207237888.

The previous prime is 210121369. The next prime is 210121423. The reversal of 210121421 is 124121012.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 12859396 + 197262025 = 3586^2 + 14045^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 210121421 - 2¹⁴ = 210105037 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 210121396 and 210121405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210121423) 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 7 ways as a sum of consecutive naturals, for example, 16625 + ... + 26393.

It is an arithmetic number, because the mean of its divisors is an integer number (26628135).

Almost surely, 2^210121421 is an apocalyptic number.

It is an amenable number.

210121421 is a deficient number, since it is larger than the sum of its proper divisors (2903659).

210121421 is a wasteful number, since it uses less digits than its factorization.

210121421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10063.

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

The square root of 210121421 is about 14495.5655633025. The cubic root of 210121421 is about 594.5067314500.

Adding to 210121421 its reverse (124121012), we get a palindrome (334242433).

The spelling of 210121421 in words is "two hundred ten million, one hundred twenty-one thousand, four hundred twenty-one".