1220131021 has 4 divisors (see below), whose sum is σ = 1291903452. Its totient is φ = 1148358592.

The previous prime is 1220131001. The next prime is 1220131027. The reversal of 1220131021 is 1201310221.

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 609349225 + 610781796 = 24685^2 + 24714^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1220131021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220130992 and 1220131010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220131027) 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, 35886190 + ... + 35886223.

It is an arithmetic number, because the mean of its divisors is an integer number (322975863).

Almost surely, 2^1220131021 is an apocalyptic number.

It is an amenable number.

1220131021 is a deficient number, since it is larger than the sum of its proper divisors (71772431).

1220131021 is an equidigital number, since it uses as much as digits as its factorization.

1220131021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71772430.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1220131021 is about 34930.3739029516. The cubic root of 1220131021 is about 1068.5679801003.

Adding to 1220131021 its reverse (1201310221), we get a palindrome (2421441242).

It can be divided in two parts, 1 and 220131021, that added together give a palindrome (220131022).

The spelling of 1220131021 in words is "one billion, two hundred twenty million, one hundred thirty-one thousand, twenty-one".