210122021 has 2 divisors, whose sum is σ = 210122022. Its totient is φ = 210122020.

The previous prime is 210121981. The next prime is 210122039. The reversal of 210122021 is 120221012.

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., 166693921 + 43428100 = 12911^2 + 6590^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-210122021 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 210121993 and 210122011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (210122071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105061010 + 105061011.

It is an arithmetic number, because the mean of its divisors is an integer number (105061011).

Almost surely, 2^210122021 is an apocalyptic number.

It is an amenable number.

210122021 is a deficient number, since it is larger than the sum of its proper divisors (1).

210122021 is an equidigital number, since it uses as much as digits as its factorization.

210122021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 210122021 is about 14495.5862592722. The cubic root of 210122021 is about 594.5072973192.

Adding to 210122021 its reverse (120221012), we get a palindrome (330343033).

The spelling of 210122021 in words is "two hundred ten million, one hundred twenty-two thousand, twenty-one".