1820220621 has 8 divisors (see below), whose sum is σ = 2532480960. Its totient is φ = 1160720352.

The previous prime is 1820220599. The next prime is 1820220631. The reversal of 1820220621 is 1260220281.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1820220621 - 2¹⁷ = 1820089549 is a prime.

It is a super-2 number, since 2×1820220621² = 6626406218227251282, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1820220591 and 1820220600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1820220631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13189936 + ... + 13190073.

It is an arithmetic number, because the mean of its divisors is an integer number (316560120).

Almost surely, 2^1820220621 is an apocalyptic number.

It is an amenable number.

1820220621 is a deficient number, since it is larger than the sum of its proper divisors (712260339).

1820220621 is a wasteful number, since it uses less digits than its factorization.

1820220621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26380035.

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 1820220621 is about 42664.0436550499. The cubic root of 1820220621 is about 1220.9784815649.

The spelling of 1820220621 in words is "one billion, eight hundred twenty million, two hundred twenty thousand, six hundred twenty-one".