1220432021 has 4 divisors (see below), whose sum is σ = 1224597612. Its totient is φ = 1216266432.

The previous prime is 1220432009. The next prime is 1220432041. The reversal of 1220432021 is 1202340221.

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 882387025 + 338044996 = 29705^2 + 18386^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220432021 - 2¹⁸ = 1220169877 is a prime.

It is a super-3 number, since 3×1220432021³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220432041) 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, 2082356 + ... + 2082941.

It is an arithmetic number, because the mean of its divisors is an integer number (306149403).

Almost surely, 2^1220432021 is an apocalyptic number.

It is an amenable number.

1220432021 is a deficient number, since it is larger than the sum of its proper divisors (4165591).

1220432021 is an equidigital number, since it uses as much as digits as its factorization.

1220432021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4165590.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 1220432021 is about 34934.6822083728. The cubic root of 1220432021 is about 1068.6558429367.

Adding to 1220432021 its reverse (1202340221), we get a palindrome (2422772242).

The spelling of 1220432021 in words is "one billion, two hundred twenty million, four hundred thirty-two thousand, twenty-one".