19430981 has 2 divisors, whose sum is σ = 19430982. Its totient is φ = 19430980.

The previous prime is 19430953. The next prime is 19431011. The reversal of 19430981 is 18903491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13205956 + 6225025 = 3634^2 + 2495^2 .

It is an emirp because it is prime and its reverse (18903491) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19430981 - 2¹⁰ = 19429957 is a prime.

It is a super-2 number, since 2×19430981² = 755126045244722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19430911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9715490 + 9715491.

It is an arithmetic number, because the mean of its divisors is an integer number (9715491).

Almost surely, 2^19430981 is an apocalyptic number.

It is an amenable number.

19430981 is a deficient number, since it is larger than the sum of its proper divisors (1).

19430981 is an equidigital number, since it uses as much as digits as its factorization.

19430981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 19430981 is about 4408.0586429856. The cubic root of 19430981 is about 268.8426962734.

The spelling of 19430981 in words is "nineteen million, four hundred thirty thousand, nine hundred eighty-one".