20780171 has 8 divisors (see below), whose sum is σ = 22065120. Its totient is φ = 19502208.

The previous prime is 20780143. The next prime is 20780173. The reversal of 20780171 is 17108702.

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

It is a cyclic number.

It is not a de Polignac number, because 20780171 - 2¹⁰ = 20779147 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20780171.

It is not an unprimeable number, because it can be changed into a prime (20780173) 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, 5210 + ... + 8288.

It is an arithmetic number, because the mean of its divisors is an integer number (2758140).

Almost surely, 2^20780171 is an apocalyptic number.

20780171 is a deficient number, since it is larger than the sum of its proper divisors (1284949).

20780171 is a wasteful number, since it uses less digits than its factorization.

20780171 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3493.

The product of its (nonzero) digits is 784, while the sum is 26.

The square root of 20780171 is about 4558.5272841127. The cubic root of 20780171 is about 274.9263538327.

Adding to 20780171 its reverse (17108702), we get a palindrome (37888873).

The spelling of 20780171 in words is "twenty million, seven hundred eighty thousand, one hundred seventy-one".