19361891 has 2 divisors, whose sum is σ = 19361892. Its totient is φ = 19361890.

The previous prime is 19361857. The next prime is 19361917. The reversal of 19361891 is 19816391.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19361891 - 2¹⁸ = 19099747 is a prime.

It is not a weakly prime, because it can be changed into another prime (19361291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9680945 + 9680946.

It is an arithmetic number, because the mean of its divisors is an integer number (9680946).

Almost surely, 2^19361891 is an apocalyptic number.

19361891 is a deficient number, since it is larger than the sum of its proper divisors (1).

19361891 is an equidigital number, since it uses as much as digits as its factorization.

19361891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11664, while the sum is 38.

The square root of 19361891 is about 4400.2148811166. The cubic root of 19361891 is about 268.5236799532.

The spelling of 19361891 in words is "nineteen million, three hundred sixty-one thousand, eight hundred ninety-one".