21339811 has 8 divisors (see below), whose sum is σ = 23324544. Its totient is φ = 19436160.

The previous prime is 21339809. The next prime is 21339821. The reversal of 21339811 is 11893312.

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 21339811 - 2¹ = 21339809 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21339811.

It is not an unprimeable number, because it can be changed into a prime (21339821) 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, 19720 + ... + 20773.

It is an arithmetic number, because the mean of its divisors is an integer number (2915568).

Almost surely, 2^21339811 is an apocalyptic number.

21339811 is a deficient number, since it is larger than the sum of its proper divisors (1984733).

21339811 is a wasteful number, since it uses less digits than its factorization.

21339811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40541.

The product of its digits is 1296, while the sum is 28.

The square root of 21339811 is about 4619.5033282811. The cubic root of 21339811 is about 277.3725779197.

The spelling of 21339811 in words is "twenty-one million, three hundred thirty-nine thousand, eight hundred eleven".