21384011 has 16 divisors (see below), whose sum is σ = 24880608. Its totient is φ = 18163200.

The previous prime is 21383969. The next prime is 21384061. The reversal of 21384011 is 11048312.

It is a de Polignac number, because none of the positive numbers 2^k-21384011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21384061) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32021 + ... + 32681.

It is an arithmetic number, because the mean of its divisors is an integer number (1555038).

Almost surely, 2^21384011 is an apocalyptic number.

21384011 is a deficient number, since it is larger than the sum of its proper divisors (3496597).

21384011 is a wasteful number, since it uses less digits than its factorization.

21384011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 862.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 21384011 is about 4624.2849176927. The cubic root of 21384011 is about 277.5639481442.

The spelling of 21384011 in words is "twenty-one million, three hundred eighty-four thousand, eleven".