21414561 has 8 divisors (see below), whose sum is σ = 32631744. Its totient is φ = 12236880.

The previous prime is 21414551. The next prime is 21414571. The reversal of 21414561 is 16541412.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21414551) and next prime (21414571).

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

It is not a de Polignac number, because 21414561 - 2⁵ = 21414529 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21414551) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 509850 + ... + 509891.

It is an arithmetic number, because the mean of its divisors is an integer number (4078968).

Almost surely, 2^21414561 is an apocalyptic number.

21414561 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21414561 is a deficient number, since it is larger than the sum of its proper divisors (11217183).

21414561 is a wasteful number, since it uses less digits than its factorization.

21414561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1019751.

The product of its digits is 960, while the sum is 24.

The square root of 21414561 is about 4627.5869521814. The cubic root of 21414561 is about 277.6960646702.

Adding to 21414561 its reverse (16541412), we get a palindrome (37955973).

The spelling of 21414561 in words is "twenty-one million, four hundred fourteen thousand, five hundred sixty-one".