20688337 has 4 divisors (see below), whose sum is σ = 21905316. Its totient is φ = 19471360.

The previous prime is 20688329. The next prime is 20688341. The reversal of 20688337 is 73388602.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16842816 + 3845521 = 4104^2 + 1961^2 .

It is a cyclic number.

It is not a de Polignac number, because 20688337 - 2³ = 20688329 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20688296 and 20688305.

It is not an unprimeable number, because it can be changed into a prime (20680337) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 608464 + ... + 608497.

It is an arithmetic number, because the mean of its divisors is an integer number (5476329).

Almost surely, 2^20688337 is an apocalyptic number.

It is an amenable number.

20688337 is a deficient number, since it is larger than the sum of its proper divisors (1216979).

20688337 is a wasteful number, since it uses less digits than its factorization.

20688337 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1216978.

The product of its (nonzero) digits is 48384, while the sum is 37.

The square root of 20688337 is about 4548.4433600958. The cubic root of 20688337 is about 274.5207609134.

It can be divided in two parts, 20688 and 337, that added together give a square (21025 = 145²).

The spelling of 20688337 in words is "twenty million, six hundred eighty-eight thousand, three hundred thirty-seven".