210405252442421 has 2 divisors, whose sum is σ = 210405252442422. Its totient is φ = 210405252442420.

The previous prime is 210405252442381. The next prime is 210405252442433. The reversal of 210405252442421 is 124244252504012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 191223567946321 + 19181684496100 = 13828361^2 + 4379690^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-210405252442421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (210405252441421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105202626221210 + 105202626221211.

It is an arithmetic number, because the mean of its divisors is an integer number (105202626221211).

Almost surely, 2^{210405252442421} is an apocalyptic number.

It is an amenable number.

210405252442421 is a deficient number, since it is larger than the sum of its proper divisors (1).

210405252442421 is an equidigital number, since it uses as much as digits as its factorization.

210405252442421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 204800, while the sum is 38.

The spelling of 210405252442421 in words is "two hundred ten trillion, four hundred five billion, two hundred fifty-two million, four hundred forty-two thousand, four hundred twenty-one".