19979161 has 2 divisors, whose sum is σ = 19979162. Its totient is φ = 19979160.

The previous prime is 19979143. The next prime is 19979213. The reversal of 19979161 is 16197991.

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., 10523536 + 9455625 = 3244^2 + 3075^2 .

It is a cyclic number.

It is not a de Polignac number, because 19979161 - 2⁵ = 19979129 is a prime.

It is not a weakly prime, because it can be changed into another prime (19979101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9989580 + 9989581.

It is an arithmetic number, because the mean of its divisors is an integer number (9989581).

Almost surely, 2^19979161 is an apocalyptic number.

It is an amenable number.

19979161 is a deficient number, since it is larger than the sum of its proper divisors (1).

19979161 is an equidigital number, since it uses as much as digits as its factorization.

19979161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30618, while the sum is 43.

The square root of 19979161 is about 4469.8054767518. The cubic root of 19979161 is about 271.3474526490.

The spelling of 19979161 in words is "nineteen million, nine hundred seventy-nine thousand, one hundred sixty-one".