512221021 has 4 divisors (see below), whose sum is σ = 551622652. Its totient is φ = 472819392.

The previous prime is 512221001. The next prime is 512221049. The reversal of 512221021 is 120122215.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 333464121 + 178756900 = 18261^2 + 13370^2 .

It is a cyclic number.

It is not a de Polignac number, because 512221021 - 2⁷ = 512220893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 512220986 and 512221004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (512221001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19700796 + ... + 19700821.

It is an arithmetic number, because the mean of its divisors is an integer number (137905663).

Almost surely, 2^512221021 is an apocalyptic number.

It is an amenable number.

512221021 is a deficient number, since it is larger than the sum of its proper divisors (39401631).

512221021 is a wasteful number, since it uses less digits than its factorization.

512221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39401630.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 512221021 is about 22632.3003912550. The cubic root of 512221021 is about 800.1150985438.

Adding to 512221021 its reverse (120122215), we get a palindrome (632343236).

The spelling of 512221021 in words is "five hundred twelve million, two hundred twenty-one thousand, twenty-one".