9819961 has 2 divisors, whose sum is σ = 9819962. Its totient is φ = 9819960.

The previous prime is 9819959. The next prime is 9819967. The reversal of 9819961 is 1699189.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9114361 + 705600 = 3019^2 + 840^2 .

It is a cyclic number.

It is not a de Polignac number, because 9819961 - 2¹ = 9819959 is a prime.

Together with 9819959, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (9819967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4909980 + 4909981.

It is an arithmetic number, because the mean of its divisors is an integer number (4909981).

Almost surely, 2^9819961 is an apocalyptic number.

It is an amenable number.

9819961 is a deficient number, since it is larger than the sum of its proper divisors (1).

9819961 is an equidigital number, since it uses as much as digits as its factorization.

9819961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34992, while the sum is 43.

The square root of 9819961 is about 3133.6817004923. The cubic root of 9819961 is about 214.1426902324.

The spelling of 9819961 in words is "nine million, eight hundred nineteen thousand, nine hundred sixty-one".