21600451 has 2 divisors, whose sum is σ = 21600452. Its totient is φ = 21600450.

The previous prime is 21600437. The next prime is 21600463. The reversal of 21600451 is 15400612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21600451 - 2⁵ = 21600419 is a prime.

It is not a weakly prime, because it can be changed into another prime (21603451) 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 as a sum of consecutive naturals, namely, 10800225 + 10800226.

It is an arithmetic number, because the mean of its divisors is an integer number (10800226).

Almost surely, 2^21600451 is an apocalyptic number.

21600451 is a deficient number, since it is larger than the sum of its proper divisors (1).

21600451 is an equidigital number, since it uses as much as digits as its factorization.

21600451 is an odious number, because the sum of its binary digits is odd.

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

The square root of 21600451 is about 4647.6285350703. The cubic root of 21600451 is about 278.4972682964.

The spelling of 21600451 in words is "twenty-one million, six hundred thousand, four hundred fifty-one".