21873471 has 16 divisors (see below), whose sum is σ = 30357504. Its totient is φ = 13997984.

The previous prime is 21873451. The next prime is 21873497. The reversal of 21873471 is 17437812.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21873471 - 2⁷ = 21873343 is a prime.

It is a super-3 number, since 3×21873471³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21873421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6010 + ... + 8936.

It is an arithmetic number, because the mean of its divisors is an integer number (1897344).

Almost surely, 2^21873471 is an apocalyptic number.

21873471 is a deficient number, since it is larger than the sum of its proper divisors (8484033).

21873471 is a wasteful number, since it uses less digits than its factorization.

21873471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3030.

The product of its digits is 9408, while the sum is 33.

The square root of 21873471 is about 4676.9082736355. The cubic root of 21873471 is about 279.6657192718.

The spelling of 21873471 in words is "twenty-one million, eight hundred seventy-three thousand, four hundred seventy-one".