21338571 has 16 divisors (see below), whose sum is σ = 29542400. Its totient is φ = 13685760.

The previous prime is 21338563. The next prime is 21338579. The reversal of 21338571 is 17583312.

It is an interprime number because it is at equal distance from previous prime (21338563) and next prime (21338579).

It is not a de Polignac number, because 21338571 - 2³ = 21338563 is a prime.

It is a super-2 number, since 2×21338571² = 910669224644082, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21338579) 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 15 ways as a sum of consecutive naturals, for example, 17931 + ... + 19083.

It is an arithmetic number, because the mean of its divisors is an integer number (1846400).

Almost surely, 2^21338571 is an apocalyptic number.

21338571 is a deficient number, since it is larger than the sum of its proper divisors (8203829).

21338571 is a wasteful number, since it uses less digits than its factorization.

21338571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1386.

The product of its digits is 5040, while the sum is 30.

The square root of 21338571 is about 4619.3691127685. The cubic root of 21338571 is about 277.3672053532.

The spelling of 21338571 in words is "twenty-one million, three hundred thirty-eight thousand, five hundred seventy-one".