20919018 has 16 divisors (see below), whose sum is σ = 41887296. Its totient is φ = 6964800.

The previous prime is 20919011. The next prime is 20919037. The reversal of 20919018 is 81091902.

It is not an unprimeable number, because it can be changed into a prime (20919011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5755 + ... + 8657.

It is an arithmetic number, because the mean of its divisors is an integer number (2617956).

Almost surely, 2^20919018 is an apocalyptic number.

20919018 is an abundant number, since it is smaller than the sum of its proper divisors (20968278).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20919018 is a wasteful number, since it uses less digits than its factorization.

20919018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4109.

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 20919018 is about 4573.7312994972. The cubic root of 20919018 is about 275.5373207983.

The spelling of 20919018 in words is "twenty million, nine hundred nineteen thousand, eighteen".