20881417 has 4 divisors (see below), whose sum is σ = 21275460. Its totient is φ = 20487376.

The previous prime is 20881381. The next prime is 20881433. The reversal of 20881417 is 71418802.

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

It can be written as a sum of positive squares in 2 ways, for example, as 18139081 + 2742336 = 4259^2 + 1656^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20881417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20881477) 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, 196942 + ... + 197047.

It is an arithmetic number, because the mean of its divisors is an integer number (5318865).

Almost surely, 2^20881417 is an apocalyptic number.

It is an amenable number.

20881417 is a deficient number, since it is larger than the sum of its proper divisors (394043).

20881417 is an equidigital number, since it uses as much as digits as its factorization.

20881417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394042.

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 20881417 is about 4569.6189119006. The cubic root of 20881417 is about 275.3721331127.

The spelling of 20881417 in words is "twenty million, eight hundred eighty-one thousand, four hundred seventeen".