19961371 has 2 divisors, whose sum is σ = 19961372. Its totient is φ = 19961370.

The previous prime is 19961369. The next prime is 19961393. The reversal of 19961371 is 17316991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19961371 - 2¹ = 19961369 is a prime.

Together with 19961369, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 19961371.

It is not a weakly prime, because it can be changed into another prime (19961321) 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, 9980685 + 9980686.

It is an arithmetic number, because the mean of its divisors is an integer number (9980686).

Almost surely, 2^19961371 is an apocalyptic number.

19961371 is a deficient number, since it is larger than the sum of its proper divisors (1).

19961371 is an equidigital number, since it uses as much as digits as its factorization.

19961371 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10206, while the sum is 37.

The square root of 19961371 is about 4467.8150140757. The cubic root of 19961371 is about 271.2668902958.

The spelling of 19961371 in words is "nineteen million, nine hundred sixty-one thousand, three hundred seventy-one".