1221020 has 12 divisors (see below), whose sum is σ = 2564184. Its totient is φ = 488400.

The previous prime is 1221019. The next prime is 1221029. The reversal of 1221020 is 201221.

1221020 = T₁₇₁ + T₁₇₂ + ... + T₂₃₀.

It is a junction number, because it is equal to n+sod(n) for n = 1220989 and 1221007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221029) 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, 30506 + ... + 30545.

It is an arithmetic number, because the mean of its divisors is an integer number (213682).

2^1221020 is an apocalyptic number.

1221020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221020 is an abundant number, since it is smaller than the sum of its proper divisors (1343164).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221020 is a wasteful number, since it uses less digits than its factorization.

1221020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61060 (or 61058 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 8.

The square root of 1221020 is about 1104.9977375542. The cubic root of 1221020 is about 106.8827434172.

Adding to 1221020 its reverse (201221), we get a palindrome (1422241).

The spelling of 1221020 in words is "one million, two hundred twenty-one thousand, twenty".