21998027 has 2 divisors, whose sum is σ = 21998028. Its totient is φ = 21998026.

The previous prime is 21997981. The next prime is 21998033. The reversal of 21998027 is 72089912.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21998027 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21998927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10999013 + 10999014.

It is an arithmetic number, because the mean of its divisors is an integer number (10999014).

Almost surely, 2^21998027 is an apocalyptic number.

21998027 is a deficient number, since it is larger than the sum of its proper divisors (1).

21998027 is an equidigital number, since it uses as much as digits as its factorization.

21998027 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 21998027 is about 4690.2054326010. The cubic root of 21998027 is about 280.1955564157.

The spelling of 21998027 in words is "twenty-one million, nine hundred ninety-eight thousand, twenty-seven".