19994805 has 48 divisors (see below), whose sum is σ = 37402560. Its totient is φ = 9844224.

The previous prime is 19994803. The next prime is 19994809. The reversal of 19994805 is 50849991.

It is not a de Polignac number, because 19994805 - 2¹ = 19994803 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19994801) 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 47 ways as a sum of consecutive naturals, for example, 44914 + ... + 45356.

It is an arithmetic number, because the mean of its divisors is an integer number (779220).

Almost surely, 2^19994805 is an apocalyptic number.

19994805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19994805 is a deficient number, since it is larger than the sum of its proper divisors (17407755).

19994805 is a wasteful number, since it uses less digits than its factorization.

19994805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 530 (or 527 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 45.

The square root of 19994805 is about 4471.5550986206. Note that the first 3 decimals coincide. The cubic root of 19994805 is about 271.4182572918.

The spelling of 19994805 in words is "nineteen million, nine hundred ninety-four thousand, eight hundred five".