21481376 has 48 divisors (see below), whose sum is σ = 49533120. Its totient is φ = 8977920.

The previous prime is 21481337. The next prime is 21481399. The reversal of 21481376 is 67318412.

It is a super-2 number, since 2×21481376² = 922899029706752, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8015 + ... + 10353.

It is an arithmetic number, because the mean of its divisors is an integer number (1031940).

Almost surely, 2^21481376 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21481376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24766560).

21481376 is an abundant number, since it is smaller than the sum of its proper divisors (28051744).

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

21481376 is a wasteful number, since it uses less digits than its factorization.

21481376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2397 (or 2389 counting only the distinct ones).

The product of its digits is 8064, while the sum is 32.

The square root of 21481376 is about 4634.8005350824. The cubic root of 21481376 is about 277.9845755119.

Adding to 21481376 its reverse (67318412), we get a palindrome (88799788).

The spelling of 21481376 in words is "twenty-one million, four hundred eighty-one thousand, three hundred seventy-six".