20564407 has 4 divisors (see below), whose sum is σ = 21774096. Its totient is φ = 19354720.

The previous prime is 20564399. The next prime is 20564431. The reversal of 20564407 is 70446502.

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

It is a cyclic number.

It is not a de Polignac number, because 20564407 - 2³ = 20564399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20564207) 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, 604819 + ... + 604852.

It is an arithmetic number, because the mean of its divisors is an integer number (5443524).

Almost surely, 2^20564407 is an apocalyptic number.

20564407 is a deficient number, since it is larger than the sum of its proper divisors (1209689).

20564407 is a wasteful number, since it uses less digits than its factorization.

20564407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1209688.

The product of its (nonzero) digits is 6720, while the sum is 28.

The square root of 20564407 is about 4534.7995545559. The cubic root of 20564407 is about 273.9715059079.

The spelling of 20564407 in words is "twenty million, five hundred sixty-four thousand, four hundred seven".