20317145 has 4 divisors (see below), whose sum is σ = 24380580. Its totient is φ = 16253712.

The previous prime is 20317127. The next prime is 20317163. The reversal of 20317145 is 54171302.

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

It is an interprime number because it is at equal distance from previous prime (20317127) and next prime (20317163).

It can be written as a sum of positive squares in 2 ways, for example, as 7038409 + 13278736 = 2653^2 + 3644^2 .

It is a cyclic number.

It is not a de Polignac number, because 20317145 - 2¹⁸ = 20055001 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20317145.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2031710 + ... + 2031719.

It is an arithmetic number, because the mean of its divisors is an integer number (6095145).

Almost surely, 2^20317145 is an apocalyptic number.

It is an amenable number.

20317145 is a deficient number, since it is larger than the sum of its proper divisors (4063435).

20317145 is an equidigital number, since it uses as much as digits as its factorization.

20317145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4063434.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 20317145 is about 4507.4543813554. The cubic root of 20317145 is about 272.8690172107.

Adding to 20317145 its reverse (54171302), we get a palindrome (74488447).

The spelling of 20317145 in words is "twenty million, three hundred seventeen thousand, one hundred forty-five".