21368541 has 16 divisors (see below), whose sum is σ = 31480704. Its totient is φ = 12824064.

The previous prime is 21368539. The next prime is 21368569. The reversal of 21368541 is 14586312.

It is not a de Polignac number, because 21368541 - 2¹ = 21368539 is a prime.

It is a super-2 number, since 2×21368541² = 913229088937362, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21368499 and 21368508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21368531) 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, 7936 + ... + 10281.

It is an arithmetic number, because the mean of its divisors is an integer number (1967544).

Almost surely, 2^21368541 is an apocalyptic number.

It is an amenable number.

21368541 is a deficient number, since it is larger than the sum of its proper divisors (10112163).

21368541 is a wasteful number, since it uses less digits than its factorization.

21368541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18260.

The product of its digits is 5760, while the sum is 30.

The square root of 21368541 is about 4622.6119240101. The cubic root of 21368541 is about 277.4969985878.

The spelling of 21368541 in words is "twenty-one million, three hundred sixty-eight thousand, five hundred forty-one".