19516961 has 4 divisors (see below), whose sum is σ = 19538112. Its totient is φ = 19495812.

The previous prime is 19516957. The next prime is 19516963. The reversal of 19516961 is 16961591.

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: 16961591 = 239 ⋅70969.

It is a cyclic number.

It is not a de Polignac number, because 19516961 - 2² = 19516957 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19516963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9125 + ... + 11058.

It is an arithmetic number, because the mean of its divisors is an integer number (4884528).

Almost surely, 2^19516961 is an apocalyptic number.

It is an amenable number.

19516961 is a deficient number, since it is larger than the sum of its proper divisors (21151).

19516961 is an equidigital number, since it uses as much as digits as its factorization.

19516961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21150.

The product of its digits is 14580, while the sum is 38.

The square root of 19516961 is about 4417.8004708226. The cubic root of 19516961 is about 269.2386461683.

The spelling of 19516961 in words is "nineteen million, five hundred sixteen thousand, nine hundred sixty-one".