19213661 has 2 divisors, whose sum is σ = 19213662. Its totient is φ = 19213660.

The previous prime is 19213637. The next prime is 19213679. The reversal of 19213661 is 16631291.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16556761 + 2656900 = 4069^2 + 1630^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19213661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19213361) 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, 9606830 + 9606831.

It is an arithmetic number, because the mean of its divisors is an integer number (9606831).

Almost surely, 2^19213661 is an apocalyptic number.

It is an amenable number.

19213661 is a deficient number, since it is larger than the sum of its proper divisors (1).

19213661 is an equidigital number, since it uses as much as digits as its factorization.

19213661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1944, while the sum is 29.

The square root of 19213661 is about 4383.3390240774. The cubic root of 19213661 is about 267.8366727790.

The spelling of 19213661 in words is "nineteen million, two hundred thirteen thousand, six hundred sixty-one".