9919961 has 4 divisors (see below), whose sum is σ = 10131072. Its totient is φ = 9708852.

The previous prime is 9919939. The next prime is 9919963. The reversal of 9919961 is 1699199.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1699199 = 953 ⋅1783.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9919961 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (9919963) 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, 105485 + ... + 105578.

It is an arithmetic number, because the mean of its divisors is an integer number (2532768).

Almost surely, 2^9919961 is an apocalyptic number.

It is an amenable number.

9919961 is a deficient number, since it is larger than the sum of its proper divisors (211111).

9919961 is a wasteful number, since it uses less digits than its factorization.

9919961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211110.

The product of its digits is 39366, while the sum is 44.

The square root of 9919961 is about 3149.5969583424. The cubic root of 9919961 is about 214.8671326171.

The spelling of 9919961 in words is "nine million, nine hundred nineteen thousand, nine hundred sixty-one".