202120421 has 2 divisors, whose sum is σ = 202120422. Its totient is φ = 202120420.

The previous prime is 202120417. The next prime is 202120427. The reversal of 202120421 is 124021202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 182628196 + 19492225 = 13514^2 + 4415^2 .

It is a cyclic number.

It is not a de Polignac number, because 202120421 - 2² = 202120417 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 202120396 and 202120405.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (202120427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101060210 + 101060211.

It is an arithmetic number, because the mean of its divisors is an integer number (101060211).

Almost surely, 2^202120421 is an apocalyptic number.

It is an amenable number.

202120421 is a deficient number, since it is larger than the sum of its proper divisors (1).

202120421 is an equidigital number, since it uses as much as digits as its factorization.

202120421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 202120421 is about 14216.9061683617. The cubic root of 202120421 is about 586.8630027190.

Adding to 202120421 its reverse (124021202), we get a palindrome (326141623).

The spelling of 202120421 in words is "two hundred two million, one hundred twenty thousand, four hundred twenty-one".