21280159 has 2 divisors, whose sum is σ = 21280160. Its totient is φ = 21280158.

The previous prime is 21280153. The next prime is 21280163. The reversal of 21280159 is 95108212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21280159 - 2¹¹ = 21278111 is a prime.

It is equal to p_1346554 and since 21280159 and 1346554 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21280153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10640079 + 10640080.

It is an arithmetic number, because the mean of its divisors is an integer number (10640080).

Almost surely, 2^21280159 is an apocalyptic number.

21280159 is a deficient number, since it is larger than the sum of its proper divisors (1).

21280159 is an equidigital number, since it uses as much as digits as its factorization.

21280159 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 21280159 is about 4613.0422716468. The cubic root of 21280159 is about 277.1138866240.

The spelling of 21280159 in words is "twenty-one million, two hundred eighty thousand, one hundred fifty-nine".