21481600 has 144 divisors (see below), whose sum is σ = 62180730. Its totient is φ = 7311360.

The previous prime is 21481597. The next prime is 21481613. The reversal of 21481600 is 618412.

21481600 = T₂₅₁ + T₂₅₂ + ... + T₅₂₄.

21481600 = 326² + 327² + ... + 462².

It can be written as a sum of positive squares in 3 ways, for example, as 16711744 + 4769856 = 4088^2 + 2184^2 .

It is a super-2 number, since 2×21481600² = 922918277120000, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 156732 + ... + 156868.

Almost surely, 2^21481600 is an apocalyptic number.

21481600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21481600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31090365).

21481600 is an abundant number, since it is smaller than the sum of its proper divisors (40699130).

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

21481600 is a wasteful number, since it uses less digits than its factorization.

21481600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175 (or 151 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 21481600 is about 4634.8247000291. The cubic root of 21481600 is about 277.9855417493.

The spelling of 21481600 in words is "twenty-one million, four hundred eighty-one thousand, six hundred".