13664642 has 4 divisors (see below), whose sum is σ = 20496966. Its totient is φ = 6832320.

The previous prime is 13664627. The next prime is 13664647. The reversal of 13664642 is 24646631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24646631 = 3607 ⋅6833.

It can be written as a sum of positive squares in only one way, i.e., 11417641 + 2247001 = 3379^2 + 1499^2 .

It is a junction number, because it is equal to n+sod(n) for n = 13664599 and 13664608.

It is not an unprimeable number, because it can be changed into a prime (13664647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3416159 + ... + 3416162.

Almost surely, 2^13664642 is an apocalyptic number.

13664642 is a deficient number, since it is larger than the sum of its proper divisors (6832324).

13664642 is an equidigital number, since it uses as much as digits as its factorization.

13664642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6832323.

The product of its digits is 20736, while the sum is 32.

The square root of 13664642 is about 3696.5716549257. The cubic root of 13664642 is about 239.0742228463.

The spelling of 13664642 in words is "thirteen million, six hundred sixty-four thousand, six hundred forty-two".