18953947 has 4 divisors (see below), whose sum is σ = 19220976. Its totient is φ = 18686920.

The previous prime is 18953941. The next prime is 18953983. The reversal of 18953947 is 74935981.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74935981 = 19 ⋅3943999.

It is a cyclic number.

It is not a de Polignac number, because 18953947 - 2¹⁵ = 18921179 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 18953897 and 18953906.

It is not an unprimeable number, because it can be changed into a prime (18953941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 133408 + ... + 133549.

It is an arithmetic number, because the mean of its divisors is an integer number (4805244).

Almost surely, 2^18953947 is an apocalyptic number.

18953947 is a deficient number, since it is larger than the sum of its proper divisors (267029).

18953947 is an equidigital number, since it uses as much as digits as its factorization.

18953947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267028.

The product of its digits is 272160, while the sum is 46.

The square root of 18953947 is about 4353.6130971872. The cubic root of 18953947 is about 266.6243976406.

It can be divided in two parts, 18953 and 947, that added together give a triangular number (19900 = T₁₉₉).

The spelling of 18953947 in words is "eighteen million, nine hundred fifty-three thousand, nine hundred forty-seven".