19461661 has 2 divisors, whose sum is σ = 19461662. Its totient is φ = 19461660.

The previous prime is 19461649. The next prime is 19461683. The reversal of 19461661 is 16616491.

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., 12602500 + 6859161 = 3550^2 + 2619^2 .

It is an emirp because it is prime and its reverse (16616491) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19461661 - 2²¹ = 17364509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19461641) 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, 9730830 + 9730831.

It is an arithmetic number, because the mean of its divisors is an integer number (9730831).

Almost surely, 2^19461661 is an apocalyptic number.

It is an amenable number.

19461661 is a deficient number, since it is larger than the sum of its proper divisors (1).

19461661 is an equidigital number, since it uses as much as digits as its factorization.

19461661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 34.

The square root of 19461661 is about 4411.5372604116. The cubic root of 19461661 is about 268.9841157363.

The spelling of 19461661 in words is "nineteen million, four hundred sixty-one thousand, six hundred sixty-one".