18949215 has 16 divisors (see below), whose sum is σ = 31297536. Its totient is φ = 9780000.

The previous prime is 18949211. The next prime is 18949243. The reversal of 18949215 is 51294981.

It is not a de Polignac number, because 18949215 - 2² = 18949211 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18949211) 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, 19911 + ... + 20840.

It is an arithmetic number, because the mean of its divisors is an integer number (1956096).

Almost surely, 2^18949215 is an apocalyptic number.

18949215 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

18949215 is a deficient number, since it is larger than the sum of its proper divisors (12348321).

18949215 is a wasteful number, since it uses less digits than its factorization.

18949215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40790.

The product of its digits is 25920, while the sum is 39.

The square root of 18949215 is about 4353.0696066109. The cubic root of 18949215 is about 266.6022075103.

The spelling of 18949215 in words is "eighteen million, nine hundred forty-nine thousand, two hundred fifteen".