20709356 has 6 divisors (see below), whose sum is σ = 36241380. Its totient is φ = 10354676.

The previous prime is 20709347. The next prime is 20709391. The reversal of 20709356 is 65390702.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2588666 + ... + 2588673.

It is an arithmetic number, because the mean of its divisors is an integer number (6040230).

Almost surely, 2^20709356 is an apocalyptic number.

It is an amenable number.

20709356 is a deficient number, since it is larger than the sum of its proper divisors (15532024).

20709356 is a wasteful number, since it uses less digits than its factorization.

20709356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5177343 (or 5177341 counting only the distinct ones).

The product of its (nonzero) digits is 11340, while the sum is 32.

The square root of 20709356 is about 4550.7533442277. The cubic root of 20709356 is about 274.6136989272.

The spelling of 20709356 in words is "twenty million, seven hundred nine thousand, three hundred fifty-six".