1220143021 has 4 divisors (see below), whose sum is σ = 1220283612. Its totient is φ = 1220002432.

The previous prime is 1220143003. The next prime is 1220143033. The reversal of 1220143021 is 1203410221.

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 113848900 + 1106294121 = 10670^2 + 33261^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220143021 - 2⁹ = 1220142509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220142986 and 1220143004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220143061) 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, 56356 + ... + 74941.

It is an arithmetic number, because the mean of its divisors is an integer number (305070903).

Almost surely, 2^1220143021 is an apocalyptic number.

It is an amenable number.

1220143021 is a deficient number, since it is larger than the sum of its proper divisors (140591).

1220143021 is an equidigital number, since it uses as much as digits as its factorization.

1220143021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140590.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 1220143021 is about 34930.5456728062. The cubic root of 1220143021 is about 1068.5714832142.

Adding to 1220143021 its reverse (1203410221), we get a palindrome (2423553242).

The spelling of 1220143021 in words is "one billion, two hundred twenty million, one hundred forty-three thousand, twenty-one".