21416040 has 192 divisors, whose sum is σ = 76377600. Its totient is φ = 5184000.

The previous prime is 21416033. The next prime is 21416051. The reversal of 21416040 is 4061412.

21416040 is a `hidden beast` number, since 21 + 41 + 604 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 211990 + ... + 212090.

It is an arithmetic number, because the mean of its divisors is an integer number (397800).

Almost surely, 2^21416040 is an apocalyptic number.

21416040 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 21416040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38188800).

21416040 is an abundant number, since it is smaller than the sum of its proper divisors (54961560).

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

21416040 is a wasteful number, since it uses less digits than its factorization.

21416040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 21416040 is about 4627.7467519301. The cubic root of 21416040 is about 277.7024575637.

Adding to 21416040 its reverse (4061412), we get a palindrome (25477452).

The spelling of 21416040 in words is "twenty-one million, four hundred sixteen thousand, forty".