21320771 has 16 divisors (see below), whose sum is σ = 23781600. Its totient is φ = 19020288.

The previous prime is 21320749. The next prime is 21320801. The reversal of 21320771 is 17702312.

It is not a de Polignac number, because 21320771 - 2¹⁰ = 21319747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21326771) 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, 28721 + ... + 29453.

It is an arithmetic number, because the mean of its divisors is an integer number (1486350).

Almost surely, 2^21320771 is an apocalyptic number.

21320771 is a deficient number, since it is larger than the sum of its proper divisors (2460829).

21320771 is a wasteful number, since it uses less digits than its factorization.

21320771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 838.

The product of its (nonzero) digits is 588, while the sum is 23.

The square root of 21320771 is about 4617.4420407841. The cubic root of 21320771 is about 277.2900600796.

The spelling of 21320771 in words is "twenty-one million, three hundred twenty thousand, seven hundred seventy-one".