19884661 has 2 divisors, whose sum is σ = 19884662. Its totient is φ = 19884660.

The previous prime is 19884653. The next prime is 19884701. The reversal of 19884661 is 16648891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19847025 + 37636 = 4455^2 + 194^2 .

It is a cyclic number.

It is not a de Polignac number, because 19884661 - 2³ = 19884653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19885661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9942330 + 9942331.

It is an arithmetic number, because the mean of its divisors is an integer number (9942331).

Almost surely, 2^19884661 is an apocalyptic number.

It is an amenable number.

19884661 is a deficient number, since it is larger than the sum of its proper divisors (1).

19884661 is an equidigital number, since it uses as much as digits as its factorization.

19884661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 82944, while the sum is 43.

The square root of 19884661 is about 4459.2220173479. Note that the first 3 decimals coincide. The cubic root of 19884661 is about 270.9189583518.

The spelling of 19884661 in words is "nineteen million, eight hundred eighty-four thousand, six hundred sixty-one".