21255727 has 2 divisors, whose sum is σ = 21255728. Its totient is φ = 21255726.

The previous prime is 21255721. The next prime is 21255733. The reversal of 21255727 is 72755212.

It is a balanced prime because it is at equal distance from previous prime (21255721) and next prime (21255733).

It is a cyclic number.

It is not a de Polignac number, because 21255727 - 2¹⁵ = 21222959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21255721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10627863 + 10627864.

It is an arithmetic number, because the mean of its divisors is an integer number (10627864).

Almost surely, 2^21255727 is an apocalyptic number.

21255727 is a deficient number, since it is larger than the sum of its proper divisors (1).

21255727 is an equidigital number, since it uses as much as digits as its factorization.

21255727 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9800, while the sum is 31.

The square root of 21255727 is about 4610.3933671651. The cubic root of 21255727 is about 277.0077934441.

The spelling of 21255727 in words is "twenty-one million, two hundred fifty-five thousand, seven hundred twenty-seven".