19909518 has 16 divisors (see below), whose sum is σ = 40790736. Its totient is φ = 6474560.

The previous prime is 19909517. The next prime is 19909537. The reversal of 19909518 is 81590991.

It is a self number, because there is not a number n which added to its sum of digits gives 19909518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19909517) 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, 40221 + ... + 40712.

It is an arithmetic number, because the mean of its divisors is an integer number (2549421).

Almost surely, 2^19909518 is an apocalyptic number.

19909518 is an abundant number, since it is smaller than the sum of its proper divisors (20881218).

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

19909518 is a wasteful number, since it uses less digits than its factorization.

19909518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80979.

The product of its (nonzero) digits is 29160, while the sum is 42.

The square root of 19909518 is about 4462.0082922379. The cubic root of 19909518 is about 271.0317995754.

The spelling of 19909518 in words is "nineteen million, nine hundred nine thousand, five hundred eighteen".