19801291 has 2 divisors, whose sum is σ = 19801292. Its totient is φ = 19801290.

The previous prime is 19801279. The next prime is 19801297. The reversal of 19801291 is 19210891.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19801291 - 2⁷ = 19801163 is a prime.

It is a super-2 number, since 2×19801291² = 784182250533362, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19801297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9900645 + 9900646.

It is an arithmetic number, because the mean of its divisors is an integer number (9900646).

Almost surely, 2^19801291 is an apocalyptic number.

19801291 is a deficient number, since it is larger than the sum of its proper divisors (1).

19801291 is an equidigital number, since it uses as much as digits as its factorization.

19801291 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 31.

The square root of 19801291 is about 4449.8641552299. The cubic root of 19801291 is about 270.5398025578.

The spelling of 19801291 in words is "nineteen million, eight hundred one thousand, two hundred ninety-one".