21450471 has 32 divisors (see below), whose sum is σ = 33865728. Its totient is φ = 11823840.

The previous prime is 21450461. The next prime is 21450479. The reversal of 21450471 is 17405412.

It is not a de Polignac number, because 21450471 - 2⁹ = 21449959 is a prime.

It is a super-3 number, since 3×21450471³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21450479) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 101556 + ... + 101766.

It is an arithmetic number, because the mean of its divisors is an integer number (1058304).

Almost surely, 2^21450471 is an apocalyptic number.

21450471 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21450471 is a deficient number, since it is larger than the sum of its proper divisors (12415257).

21450471 is a wasteful number, since it uses less digits than its factorization.

21450471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371.

The product of its (nonzero) digits is 1120, while the sum is 24.

The square root of 21450471 is about 4631.4653188813. The cubic root of 21450471 is about 277.8512004963.

Adding to 21450471 its reverse (17405412), we get a palindrome (38855883).

The spelling of 21450471 in words is "twenty-one million, four hundred fifty thousand, four hundred seventy-one".