1220244021 has 10 divisors (see below), whose sum is σ = 1822833782. Its totient is φ = 813495960.

The previous prime is 1220244013. The next prime is 1220244029. The reversal of 1220244021 is 1204420221.

1220244021 is a `hidden beast` number, since 1 + 2 + 202 + 440 + 21 = 666.

1220244021 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (1220244013) and next prime (1220244029).

It can be written as a sum of positive squares in only one way, i.e., 614345796 + 605898225 = 24786^2 + 24615^2 .

It is not a de Polignac number, because 1220244021 - 2³ = 1220244013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220243985 and 1220244003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220244029) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 7532290 + ... + 7532451.

Almost surely, 2^1220244021 is an apocalyptic number.

It is an amenable number.

1220244021 is a deficient number, since it is larger than the sum of its proper divisors (602589761).

1220244021 is an equidigital number, since it uses as much as digits as its factorization.

1220244021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15064753 (or 15064744 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 1220244021 is about 34931.9913689443. The cubic root of 1220244021 is about 1068.6009668458.

Adding to 1220244021 its reverse (1204420221), we get a palindrome (2424664242).

The spelling of 1220244021 in words is "one billion, two hundred twenty million, two hundred forty-four thousand, twenty-one".