18949945 has 16 divisors (see below), whose sum is σ = 26379648. Its totient is φ = 12798720.

The previous prime is 18949877. The next prime is 18949949. The reversal of 18949945 is 54994981.

It is a happy number.

It is not a de Polignac number, because 18949945 - 2⁷ = 18949817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18949949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1696 + ... + 6385.

It is an arithmetic number, because the mean of its divisors is an integer number (1648728).

Almost surely, 2^18949945 is an apocalyptic number.

It is an amenable number.

18949945 is a deficient number, since it is larger than the sum of its proper divisors (7429703).

18949945 is an equidigital number, since it uses as much as digits as its factorization.

18949945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8160.

The product of its digits is 466560, while the sum is 49.

The square root of 18949945 is about 4353.1534546809. The cubic root of 18949945 is about 266.6056309963.

The spelling of 18949945 in words is "eighteen million, nine hundred forty-nine thousand, nine hundred forty-five".