21463140 has 96 divisors (see below), whose sum is σ = 63737856. Its totient is φ = 5385600.

The previous prime is 21463133. The next prime is 21463147. The reversal of 21463140 is 4136412.

It is an interprime number because it is at equal distance from previous prime (21463133) and next prime (21463147).

It is not an unprimeable number, because it can be changed into a prime (21463147) 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, 142065 + ... + 142215.

It is an arithmetic number, because the mean of its divisors is an integer number (663936).

Almost surely, 2^21463140 is an apocalyptic number.

21463140 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 21463140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31868928).

21463140 is an abundant number, since it is smaller than the sum of its proper divisors (42274716).

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

21463140 is a wasteful number, since it uses less digits than its factorization.

21463140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 289 (or 287 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 21463140 is about 4632.8328266839. The cubic root of 21463140 is about 277.9058908894.

Adding to 21463140 its reverse (4136412), we get a palindrome (25599552).

The spelling of 21463140 in words is "twenty-one million, four hundred sixty-three thousand, one hundred forty".