20706405 has 8 divisors (see below), whose sum is σ = 33130272. Its totient is φ = 11043408.

The previous prime is 20706401. The next prime is 20706407. The reversal of 20706405 is 50460702.

It is a happy number.

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

It is not a de Polignac number, because 20706405 - 2² = 20706401 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20706401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 690199 + ... + 690228.

It is an arithmetic number, because the mean of its divisors is an integer number (4141284).

Almost surely, 2^20706405 is an apocalyptic number.

It is an amenable number.

20706405 is a deficient number, since it is larger than the sum of its proper divisors (12423867).

20706405 is a wasteful number, since it uses less digits than its factorization.

20706405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1380435.

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 20706405 is about 4550.4291006453. The cubic root of 20706405 is about 274.6006545248.

The spelling of 20706405 in words is "twenty million, seven hundred six thousand, four hundred five".