20903471 has 4 divisors (see below), whose sum is σ = 20917512. Its totient is φ = 20889432.

The previous prime is 20903459. The next prime is 20903497. The reversal of 20903471 is 17430902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17430902 = 2 ⋅8715451.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20903471 is a prime.

It is a super-3 number, since 3×20903471³ (a number of 23 digits) contains 333 as substring.

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 20903471.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20903411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4481 + ... + 7866.

It is an arithmetic number, because the mean of its divisors is an integer number (5229378).

Almost surely, 2^20903471 is an apocalyptic number.

20903471 is a deficient number, since it is larger than the sum of its proper divisors (14041).

20903471 is a wasteful number, since it uses less digits than its factorization.

20903471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14040.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 20903471 is about 4572.0313865939. The cubic root of 20903471 is about 275.4690441644.

The spelling of 20903471 in words is "twenty million, nine hundred three thousand, four hundred seventy-one".