1021212505 has 4 divisors (see below), whose sum is σ = 1225455012. Its totient is φ = 816970000.

The previous prime is 1021212503. The next prime is 1021212523. The reversal of 1021212505 is 5052121201.

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 372644416 + 648568089 = 19304^2 + 25467^2 .

It is not a de Polignac number, because 1021212505 - 2¹ = 1021212503 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1021212503) 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, 102121246 + ... + 102121255.

It is an arithmetic number, because the mean of its divisors is an integer number (306363753).

Almost surely, 2^1021212505 is an apocalyptic number.

It is an amenable number.

1021212505 is a deficient number, since it is larger than the sum of its proper divisors (204242507).

1021212505 is an equidigital number, since it uses as much as digits as its factorization.

1021212505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204242506.

The product of its (nonzero) digits is 200, while the sum is 19.

The square root of 1021212505 is about 31956.4157095254. The cubic root of 1021212505 is about 1007.0214192851.

Adding to 1021212505 its reverse (5052121201), we get a palindrome (6073333706).

The spelling of 1021212505 in words is "one billion, twenty-one million, two hundred twelve thousand, five hundred five".