21869471 has 8 divisors (see below), whose sum is σ = 23951760. Its totient is φ = 19844352.

The previous prime is 21869467. The next prime is 21869473. The reversal of 21869471 is 17496812.

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 21869471 - 2² = 21869467 is a prime.

It is a super-3 number, since 3×21869471³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21869473) 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, 13490 + ... + 15023.

It is an arithmetic number, because the mean of its divisors is an integer number (2993970).

Almost surely, 2^21869471 is an apocalyptic number.

21869471 is a deficient number, since it is larger than the sum of its proper divisors (2082289).

21869471 is a wasteful number, since it uses less digits than its factorization.

21869471 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28585.

The product of its digits is 24192, while the sum is 38.

The square root of 21869471 is about 4676.4806211509. The cubic root of 21869471 is about 279.6486707495.

The spelling of 21869471 in words is "twenty-one million, eight hundred sixty-nine thousand, four hundred seventy-one".