19962661 has 2 divisors, whose sum is σ = 19962662. Its totient is φ = 19962660.

The previous prime is 19962659. The next prime is 19962713. The reversal of 19962661 is 16626991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19272100 + 690561 = 4390^2 + 831^2 .

It is a cyclic number.

It is not a de Polignac number, because 19962661 - 2¹ = 19962659 is a prime.

Together with 19962659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19962161) 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 as a sum of consecutive naturals, namely, 9981330 + 9981331.

It is an arithmetic number, because the mean of its divisors is an integer number (9981331).

Almost surely, 2^19962661 is an apocalyptic number.

It is an amenable number.

19962661 is a deficient number, since it is larger than the sum of its proper divisors (1).

19962661 is an equidigital number, since it uses as much as digits as its factorization.

19962661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34992, while the sum is 40.

The square root of 19962661 is about 4467.9593776130. The cubic root of 19962661 is about 271.2727336946.

The spelling of 19962661 in words is "nineteen million, nine hundred sixty-two thousand, six hundred sixty-one".