20688446 has 4 divisors (see below), whose sum is σ = 31032672. Its totient is φ = 10344222.

The previous prime is 20688433. The next prime is 20688463. The reversal of 20688446 is 64488602.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 64488602 = 2 ⋅32244301.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5172110 + ... + 5172113.

It is an arithmetic number, because the mean of its divisors is an integer number (7758168).

Almost surely, 2^20688446 is an apocalyptic number.

20688446 is a deficient number, since it is larger than the sum of its proper divisors (10344226).

20688446 is a wasteful number, since it uses less digits than its factorization.

20688446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10344225.

The product of its (nonzero) digits is 73728, while the sum is 38.

The square root of 20688446 is about 4548.4553422014. The cubic root of 20688446 is about 274.5212430323.

The spelling of 20688446 in words is "twenty million, six hundred eighty-eight thousand, four hundred forty-six".