19961659 has 2 divisors, whose sum is σ = 19961660. Its totient is φ = 19961658.

The previous prime is 19961653. The next prime is 19961681. The reversal of 19961659 is 95616991.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19961659 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19961653) 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, 9980829 + 9980830.

It is an arithmetic number, because the mean of its divisors is an integer number (9980830).

Almost surely, 2^19961659 is an apocalyptic number.

19961659 is a deficient number, since it is larger than the sum of its proper divisors (1).

19961659 is an equidigital number, since it uses as much as digits as its factorization.

19961659 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 131220, while the sum is 46.

The square root of 19961659 is about 4467.8472444792. The cubic root of 19961659 is about 271.2681948904.

It can be divided in two parts, 1996 and 1659, that added together give a triangular number (3655 = T₈₅).

The spelling of 19961659 in words is "nineteen million, nine hundred sixty-one thousand, six hundred fifty-nine".