21471472 has 20 divisors (see below), whose sum is σ = 45383256. Its totient is φ = 9759680.

The previous prime is 21471467. The next prime is 21471473. The reversal of 21471472 is 27417412.

It is a super-2 number, since 2×21471472² = 922048219693568, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21471472.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21471473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 60823 + ... + 61174.

Almost surely, 2^21471472 is an apocalyptic number.

21471472 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21471472 is an abundant number, since it is smaller than the sum of its proper divisors (23911784).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21471472 is a wasteful number, since it uses less digits than its factorization.

21471472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122016 (or 122010 counting only the distinct ones).

The product of its digits is 3136, while the sum is 28.

The square root of 21471472 is about 4633.7319732587. The cubic root of 21471472 is about 277.9418472984.

Adding to 21471472 its reverse (27417412), we get a palindrome (48888884).

The spelling of 21471472 in words is "twenty-one million, four hundred seventy-one thousand, four hundred seventy-two".