1220210021 has 8 divisors (see below), whose sum is σ = 1231301400. Its totient is φ = 1209157632.

The previous prime is 1220210009. The next prime is 1220210029. The reversal of 1220210021 is 1200120221.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 79459396 + 1140750625 = 8914^2 + 33775^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1220210021 - 2³⁰ = 146468197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220209984 and 1220210011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220210029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55061 + ... + 73973.

It is an arithmetic number, because the mean of its divisors is an integer number (153912675).

Almost surely, 2^1220210021 is an apocalyptic number.

It is an amenable number.

1220210021 is a deficient number, since it is larger than the sum of its proper divisors (11091379).

1220210021 is a wasteful number, since it uses less digits than its factorization.

1220210021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19495.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 1220210021 is about 34931.5047056379. The cubic root of 1220210021 is about 1068.5910418446.

Adding to 1220210021 its reverse (1200120221), we get a palindrome (2420330242).

The spelling of 1220210021 in words is "one billion, two hundred twenty million, two hundred ten thousand, twenty-one".