20945017 has 4 divisors (see below), whose sum is σ = 21340260. Its totient is φ = 20549776.

The previous prime is 20944981. The next prime is 20945039. The reversal of 20945017 is 71054902.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71054902 = 2 ⋅35527451.

It can be written as a sum of positive squares in 2 ways, for example, as 13660416 + 7284601 = 3696^2 + 2699^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20945017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20945117) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 197542 + ... + 197647.

It is an arithmetic number, because the mean of its divisors is an integer number (5335065).

Almost surely, 2^20945017 is an apocalyptic number.

It is an amenable number.

20945017 is a deficient number, since it is larger than the sum of its proper divisors (395243).

20945017 is an equidigital number, since it uses as much as digits as its factorization.

20945017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 395242.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 20945017 is about 4576.5726258850. The cubic root of 20945017 is about 275.6514231759.

Adding to 20945017 its reverse (71054902), we get a palindrome (91999919).

The spelling of 20945017 in words is "twenty million, nine hundred forty-five thousand, seventeen".