20866745 has 8 divisors (see below), whose sum is σ = 25651080. Its totient is φ = 16286080.

The previous prime is 20866733. The next prime is 20866753. The reversal of 20866745 is 54766802.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 121 + 20866624 = 11^2 + 4568^2 .

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

It is not a de Polignac number, because 20866745 - 2¹⁸ = 20604601 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20866699 and 20866708.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50690 + ... + 51099.

It is an arithmetic number, because the mean of its divisors is an integer number (3206385).

Almost surely, 2^20866745 is an apocalyptic number.

It is an amenable number.

20866745 is a deficient number, since it is larger than the sum of its proper divisors (4784335).

20866745 is a wasteful number, since it uses less digits than its factorization.

20866745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101835.

The product of its (nonzero) digits is 80640, while the sum is 38.

The square root of 20866745 is about 4568.0132442890. The cubic root of 20866745 is about 275.3076226985.

The spelling of 20866745 in words is "twenty million, eight hundred sixty-six thousand, seven hundred forty-five".