20709545 has 16 divisors (see below), whose sum is σ = 26203392. Its totient is φ = 15681600.

The previous prime is 20709539. The next prime is 20709547. The reversal of 20709545 is 54590702.

It is not a de Polignac number, because 20709545 - 2⁸ = 20709289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20709547) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10724 + ... + 12506.

It is an arithmetic number, because the mean of its divisors is an integer number (1637712).

Almost surely, 2^20709545 is an apocalyptic number.

It is an amenable number.

20709545 is a deficient number, since it is larger than the sum of its proper divisors (5493847).

20709545 is a wasteful number, since it uses less digits than its factorization.

20709545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1912.

The product of its (nonzero) digits is 12600, while the sum is 32.

The square root of 20709545 is about 4550.7741099729. The cubic root of 20709545 is about 274.6145343279.

The spelling of 20709545 in words is "twenty million, seven hundred nine thousand, five hundred forty-five".