19818794 has 4 divisors (see below), whose sum is σ = 29728194. Its totient is φ = 9909396.

The previous prime is 19818793. The next prime is 19818797. The reversal of 19818794 is 49781891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 49781891 = 607 ⋅82013.

It can be written as a sum of positive squares in only one way, i.e., 16703569 + 3115225 = 4087^2 + 1765^2 .

It is a super-2 number, since 2×19818794² = 785569191228872, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (19818793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4954697 + ... + 4954700.

Almost surely, 2^19818794 is an apocalyptic number.

19818794 is a deficient number, since it is larger than the sum of its proper divisors (9909400).

19818794 is an equidigital number, since it uses as much as digits as its factorization.

19818794 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9909399.

The product of its digits is 145152, while the sum is 47.

The square root of 19818794 is about 4451.8304100673. The cubic root of 19818794 is about 270.6194920359.

The spelling of 19818794 in words is "nineteen million, eight hundred eighteen thousand, seven hundred ninety-four".