19664474 has 4 divisors (see below), whose sum is σ = 29496714. Its totient is φ = 9832236.

The previous prime is 19664467. The next prime is 19664479. The reversal of 19664474 is 47446691.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 47446691 = 37 ⋅1282343.

It can be written as a sum of positive squares in only one way, i.e., 19298449 + 366025 = 4393^2 + 605^2 .

It is not an unprimeable number, because it can be changed into a prime (19664479) 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 as a sum of consecutive naturals, namely, 4916117 + ... + 4916120.

Almost surely, 2^19664474 is an apocalyptic number.

19664474 is a deficient number, since it is larger than the sum of its proper divisors (9832240).

19664474 is an equidigital number, since it uses as much as digits as its factorization.

19664474 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9832239.

The product of its digits is 145152, while the sum is 41.

The square root of 19664474 is about 4434.4643419471. The cubic root of 19664474 is about 269.9152637614.

The spelling of 19664474 in words is "nineteen million, six hundred sixty-four thousand, four hundred seventy-four".