1221003021 has 12 divisors (see below), whose sum is σ = 1893800832. Its totient is φ = 697715928.

The previous prime is 1221002963. The next prime is 1221003031. The reversal of 1221003021 is 1203001221.

It is not a de Polignac number, because 1221003021 - 2¹¹ = 1221000973 is a prime.

It is a super-2 number, since 2×1221003021² = 2981696754582252882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221002988 and 1221003006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221003031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4152925 + ... + 4153218.

It is an arithmetic number, because the mean of its divisors is an integer number (157816736).

Almost surely, 2^1221003021 is an apocalyptic number.

It is an amenable number.

1221003021 is a deficient number, since it is larger than the sum of its proper divisors (672797811).

1221003021 is an equidigital number, since it uses as much as digits as its factorization.

1221003021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8306160 (or 8306153 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 1221003021 is about 34942.8536470621. The cubic root of 1221003021 is about 1068.8224799243.

Adding to 1221003021 its reverse (1203001221), we get a palindrome (2424004242).

The spelling of 1221003021 in words is "one billion, two hundred twenty-one million, three thousand, twenty-one".