21501413 has 8 divisors (see below), whose sum is σ = 22861440. Its totient is φ = 20152000.

The previous prime is 21501401. The next prime is 21501451. The reversal of 21501413 is 31410512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21501413 - 2⁶ = 21501349 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21501391 and 21501400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21501713) by changing a digit.

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, 1748 + ... + 6786.

It is an arithmetic number, because the mean of its divisors is an integer number (2857680).

Almost surely, 2^21501413 is an apocalyptic number.

It is an amenable number.

21501413 is a deficient number, since it is larger than the sum of its proper divisors (1360027).

21501413 is a wasteful number, since it uses less digits than its factorization.

21501413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5307.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 21501413 is about 4636.9616129530. The cubic root of 21501413 is about 278.0709797537.

Adding to 21501413 its reverse (31410512), we get a palindrome (52911925).

Subtracting 21501413 from its reverse (31410512), we obtain a palindrome (9909099).

The spelling of 21501413 in words is "twenty-one million, five hundred one thousand, four hundred thirteen".