21384513 has 32 divisors (see below), whose sum is σ = 33868800. Its totient is φ = 13305600.

The previous prime is 21384511. The next prime is 21384529. The reversal of 21384513 is 31548312.

It is a happy number.

It is not a de Polignac number, because 21384513 - 2¹ = 21384511 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21384511) 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, 23833 + ... + 24713.

It is an arithmetic number, because the mean of its divisors is an integer number (1058400).

Almost surely, 2^21384513 is an apocalyptic number.

It is an amenable number.

21384513 is a deficient number, since it is larger than the sum of its proper divisors (12484287).

21384513 is a wasteful number, since it uses less digits than its factorization.

21384513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 950 (or 944 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 21384513 is about 4624.3391960366. The cubic root of 21384513 is about 277.5661201099.

The spelling of 21384513 in words is "twenty-one million, three hundred eighty-four thousand, five hundred thirteen".