21384507 has 8 divisors (see below), whose sum is σ = 28635984. Its totient is φ = 14194688.

The previous prime is 21384479. The next prime is 21384509. The reversal of 21384507 is 70548312.

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 21384507 - 2⁷ = 21384379 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21384509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14598 + ... + 15995.

It is an arithmetic number, because the mean of its divisors is an integer number (3579498).

Almost surely, 2^21384507 is an apocalyptic number.

21384507 is a deficient number, since it is larger than the sum of its proper divisors (7251477).

21384507 is a wasteful number, since it uses less digits than its factorization.

21384507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30829.

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 21384507 is about 4624.3385472952. The cubic root of 21384507 is about 277.5660941503.

The spelling of 21384507 in words is "twenty-one million, three hundred eighty-four thousand, five hundred seven".