512215421 has 2 divisors, whose sum is σ = 512215422. Its totient is φ = 512215420.

The previous prime is 512215397. The next prime is 512215489. The reversal of 512215421 is 124512215.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 510127396 + 2088025 = 22586^2 + 1445^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-512215421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (512215021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 256107710 + 256107711.

It is an arithmetic number, because the mean of its divisors is an integer number (256107711).

Almost surely, 2^512215421 is an apocalyptic number.

It is an amenable number.

512215421 is a deficient number, since it is larger than the sum of its proper divisors (1).

512215421 is an equidigital number, since it uses as much as digits as its factorization.

512215421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 800, while the sum is 23.

The square root of 512215421 is about 22632.1766739304. The cubic root of 512215421 is about 800.1121827056.

Adding to 512215421 its reverse (124512215), we get a palindrome (636727636).

The spelling of 512215421 in words is "five hundred twelve million, two hundred fifteen thousand, four hundred twenty-one".