20406345 has 8 divisors (see below), whose sum is σ = 32650176. Its totient is φ = 10883376.

The previous prime is 20406329. The next prime is 20406349. The reversal of 20406345 is 54360402.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20406345 - 2⁴ = 20406329 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20406349) 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 in 7 ways as a sum of consecutive naturals, for example, 680197 + ... + 680226.

It is an arithmetic number, because the mean of its divisors is an integer number (4081272).

Almost surely, 2^20406345 is an apocalyptic number.

It is an amenable number.

20406345 is a deficient number, since it is larger than the sum of its proper divisors (12243831).

20406345 is a wasteful number, since it uses less digits than its factorization.

20406345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1360431.

The product of its (nonzero) digits is 2880, while the sum is 24.

The square root of 20406345 is about 4517.3382649521. The cubic root of 20406345 is about 273.2677671739.

Adding to 20406345 its reverse (54360402), we get a palindrome (74766747).

It can be divided in two parts, 2040 and 6345, that added together give a triangular number (8385 = T₁₂₉).

The spelling of 20406345 in words is "twenty million, four hundred six thousand, three hundred forty-five".