20708906 has 4 divisors (see below), whose sum is σ = 31063362. Its totient is φ = 10354452.

The previous prime is 20708893. The next prime is 20708911. The reversal of 20708906 is 60980702.

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

It can be written as a sum of positive squares in only one way, i.e., 19280881 + 1428025 = 4391^2 + 1195^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5177225 + ... + 5177228.

Almost surely, 2^20708906 is an apocalyptic number.

20708906 is a deficient number, since it is larger than the sum of its proper divisors (10354456).

20708906 is a wasteful number, since it uses less digits than its factorization.

20708906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10354455.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 20708906 is about 4550.7039015959. The cubic root of 20708906 is about 274.6117098575.

The spelling of 20708906 in words is "twenty million, seven hundred eight thousand, nine hundred six".