19690818 has 32 divisors (see below), whose sum is σ = 46058496. Its totient is φ = 5494608.

The previous prime is 19690817. The next prime is 19690823. The reversal of 19690818 is 81809691.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 19690818.

It is not an unprimeable number, because it can be changed into a prime (19690817) 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, 3646 + ... + 7257.

It is an arithmetic number, because the mean of its divisors is an integer number (1439328).

Almost surely, 2^19690818 is an apocalyptic number.

19690818 is an abundant number, since it is smaller than the sum of its proper divisors (26367678).

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

19690818 is a wasteful number, since it uses less digits than its factorization.

19690818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10958.

The product of its (nonzero) digits is 31104, while the sum is 42.

The square root of 19690818 is about 4437.4337178148. The cubic root of 19690818 is about 270.0357428676.

The spelling of 19690818 in words is "nineteen million, six hundred ninety thousand, eight hundred eighteen".