9820621 has 2 divisors, whose sum is σ = 9820622. Its totient is φ = 9820620.

The previous prime is 9820619. The next prime is 9820627. The reversal of 9820621 is 1260289.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8094025 + 1726596 = 2845^2 + 1314^2 .

It is a cyclic number.

It is not a de Polignac number, because 9820621 - 2¹ = 9820619 is a prime.

Together with 9820619, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 9820621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9820627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4910310 + 4910311.

It is an arithmetic number, because the mean of its divisors is an integer number (4910311).

Almost surely, 2^9820621 is an apocalyptic number.

It is an amenable number.

9820621 is a deficient number, since it is larger than the sum of its proper divisors (1).

9820621 is an equidigital number, since it uses as much as digits as its factorization.

9820621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 9820621 is about 3133.7870061636. The cubic root of 9820621 is about 214.1474876381.

The spelling of 9820621 in words is "nine million, eight hundred twenty thousand, six hundred twenty-one".