1022021221 has 4 divisors (see below), whose sum is σ = 1100638252. Its totient is φ = 943404192.

The previous prime is 1022021171. The next prime is 1022021239. The reversal of 1022021221 is 1221202201.

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 508998721 + 513022500 = 22561^2 + 22650^2 .

It is a cyclic number.

It is not a de Polignac number, because 1022021221 - 2¹³ = 1022013029 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 78617017 = 1022021221 / (1 + 0 + 2 + 2 + 0 + 2 + 1 + 2 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1022021321) 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, 39308496 + ... + 39308521.

It is an arithmetic number, because the mean of its divisors is an integer number (275159563).

Almost surely, 2^1022021221 is an apocalyptic number.

It is an amenable number.

1022021221 is a deficient number, since it is larger than the sum of its proper divisors (78617031).

1022021221 is an equidigital number, since it uses as much as digits as its factorization.

1022021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78617030.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 1022021221 is about 31969.0666269755. The cubic root of 1022021221 is about 1007.2871750891.

Adding to 1022021221 its reverse (1221202201), we get a palindrome (2243223422).

The spelling of 1022021221 in words is "one billion, twenty-two million, twenty-one thousand, two hundred twenty-one".