1021312221 has 16 divisors (see below), whose sum is σ = 1431084864. Its totient is φ = 647063424.

The previous prime is 1021312219. The next prime is 1021312231. The reversal of 1021312221 is 1222131201.

It is not a de Polignac number, because 1021312221 - 2¹ = 1021312219 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1021312221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021312231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 102216 + ... + 111761.

It is an arithmetic number, because the mean of its divisors is an integer number (89442804).

Almost surely, 2^1021312221 is an apocalyptic number.

It is an amenable number.

1021312221 is a deficient number, since it is larger than the sum of its proper divisors (409772643).

1021312221 is a wasteful number, since it uses less digits than its factorization.

1021312221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214060.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1021312221 is about 31957.9758589307. The cubic root of 1021312221 is about 1007.0541949902.

Adding to 1021312221 its reverse (1222131201), we get a palindrome (2243443422).

The spelling of 1021312221 in words is "one billion, twenty-one million, three hundred twelve thousand, two hundred twenty-one".