21358641 has 8 divisors (see below), whose sum is σ = 29977120. Its totient is φ = 13489632.

The previous prime is 21358627. The next prime is 21358661. The reversal of 21358641 is 14685312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21358641 - 2⁵ = 21358609 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21358599 and 21358608.

It is not an unprimeable number, because it can be changed into a prime (21358661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 187300 + ... + 187413.

It is an arithmetic number, because the mean of its divisors is an integer number (3747140).

Almost surely, 2^21358641 is an apocalyptic number.

It is an amenable number.

21358641 is a deficient number, since it is larger than the sum of its proper divisors (8618479).

21358641 is a wasteful number, since it uses less digits than its factorization.

21358641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 374735.

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

The square root of 21358641 is about 4621.5409767739. The cubic root of 21358641 is about 277.4541373764.

The spelling of 21358641 in words is "twenty-one million, three hundred fifty-eight thousand, six hundred forty-one".