18991954 has 8 divisors (see below), whose sum is σ = 28913328. Its totient is φ = 9354180.

The previous prime is 18991949. The next prime is 18991969. The reversal of 18991954 is 45919981.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 70732 + ... + 70999.

It is an arithmetic number, because the mean of its divisors is an integer number (3614166).

Almost surely, 2^18991954 is an apocalyptic number.

18991954 is a deficient number, since it is larger than the sum of its proper divisors (9921374).

18991954 is a wasteful number, since it uses less digits than its factorization.

18991954 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141800.

The product of its digits is 116640, while the sum is 46.

The square root of 18991954 is about 4357.9759063125. The cubic root of 18991954 is about 266.8024929581.

The spelling of 18991954 in words is "eighteen million, nine hundred ninety-one thousand, nine hundred fifty-four".