21413040 has 80 divisors (see below), whose sum is σ = 72423936. Its totient is φ = 5190400.

The previous prime is 21413039. The next prime is 21413053. The reversal of 21413040 is 4031412.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1416 + ... + 6695.

Almost surely, 2^21413040 is an apocalyptic number.

21413040 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 21413040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36211968).

21413040 is an abundant number, since it is smaller than the sum of its proper divisors (51010896).

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

21413040 is a wasteful number, since it uses less digits than its factorization.

21413040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8138 (or 8132 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 21413040 is about 4627.4226087532. The cubic root of 21413040 is about 277.6894899271.

Adding to 21413040 its reverse (4031412), we get a palindrome (25444452).

The spelling of 21413040 in words is "twenty-one million, four hundred thirteen thousand, forty".