18948691 has 2 divisors, whose sum is σ = 18948692. Its totient is φ = 18948690.

The previous prime is 18948679. The next prime is 18948697. The reversal of 18948691 is 19684981.

It is a strong prime.

It is an emirp because it is prime and its reverse (19684981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18948691 - 2⁷ = 18948563 is a prime.

It is a super-2 number, since 2×18948691² = 718105781226962, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18948697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9474345 + 9474346.

It is an arithmetic number, because the mean of its divisors is an integer number (9474346).

Almost surely, 2^18948691 is an apocalyptic number.

18948691 is a deficient number, since it is larger than the sum of its proper divisors (1).

18948691 is an equidigital number, since it uses as much as digits as its factorization.

18948691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 124416, while the sum is 46.

The square root of 18948691 is about 4353.0094187814. The cubic root of 18948691 is about 266.5997500498.

It can be divided in two parts, 1894 and 8691, that added together give a triangular number (10585 = T₁₄₅).

The spelling of 18948691 in words is "eighteen million, nine hundred forty-eight thousand, six hundred ninety-one".