21480144 has 40 divisors (see below), whose sum is σ = 63418560. Its totient is φ = 6137088.

The previous prime is 21480131. The next prime is 21480157. The reversal of 21480144 is 44108412.

It is an interprime number because it is at equal distance from previous prime (21480131) and next prime (21480157).

It is a super-2 number, since 2×21480144² = 922793172521472, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 31629 + ... + 32300.

It is an arithmetic number, because the mean of its divisors is an integer number (1585464).

Almost surely, 2^21480144 is an apocalyptic number.

21480144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21480144 is an abundant number, since it is smaller than the sum of its proper divisors (41938416).

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

21480144 is a wasteful number, since it uses less digits than its factorization.

21480144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63947 (or 63941 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 24.

The square root of 21480144 is about 4634.6676256232. The cubic root of 21480144 is about 277.9792610860.

Adding to 21480144 its reverse (44108412), we get a palindrome (65588556).

The spelling of 21480144 in words is "twenty-one million, four hundred eighty thousand, one hundred forty-four".