21401065 has 8 divisors (see below), whose sum is σ = 29350080. Its totient is φ = 14674992.

The previous prime is 21401053. The next prime is 21401069. The reversal of 21401065 is 56010412.

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 21401065 - 2⁷ = 21400937 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21401069) 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, 305695 + ... + 305764.

It is an arithmetic number, because the mean of its divisors is an integer number (3668760).

Almost surely, 2^21401065 is an apocalyptic number.

It is an amenable number.

21401065 is a deficient number, since it is larger than the sum of its proper divisors (7949015).

21401065 is an equidigital number, since it uses as much as digits as its factorization.

21401065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611471.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 21401065 is about 4626.1285109690. The cubic root of 21401065 is about 277.6377153741.

Adding to 21401065 its reverse (56010412), we get a palindrome (77411477).

The spelling of 21401065 in words is "twenty-one million, four hundred one thousand, sixty-five".