21414551 has 2 divisors, whose sum is σ = 21414552. Its totient is φ = 21414550.

The previous prime is 21414529. The next prime is 21414571. The reversal of 21414551 is 15541412.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21414551 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21414571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10707275 + 10707276.

It is an arithmetic number, because the mean of its divisors is an integer number (10707276).

Almost surely, 2^21414551 is an apocalyptic number.

21414551 is a deficient number, since it is larger than the sum of its proper divisors (1).

21414551 is an equidigital number, since it uses as much as digits as its factorization.

21414551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 800, while the sum is 23.

The square root of 21414551 is about 4627.5858717046. The cubic root of 21414551 is about 277.6960214448.

Adding to 21414551 its reverse (15541412), we get a palindrome (36955963).

The spelling of 21414551 in words is "twenty-one million, four hundred fourteen thousand, five hundred fifty-one".