21888859 has 2 divisors, whose sum is σ = 21888860. Its totient is φ = 21888858.

The previous prime is 21888851. The next prime is 21888869. The reversal of 21888859 is 95888812.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21888859 - 2³ = 21888851 is a prime.

It is not a weakly prime, because it can be changed into another prime (21888851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10944429 + 10944430.

It is an arithmetic number, because the mean of its divisors is an integer number (10944430).

Almost surely, 2^21888859 is an apocalyptic number.

21888859 is a deficient number, since it is larger than the sum of its proper divisors (1).

21888859 is an equidigital number, since it uses as much as digits as its factorization.

21888859 is an evil number, because the sum of its binary digits is even.

The product of its digits is 368640, while the sum is 49.

The square root of 21888859 is about 4678.5530882956. The cubic root of 21888859 is about 279.7312855661.

The spelling of 21888859 in words is "twenty-one million, eight hundred eighty-eight thousand, eight hundred fifty-nine".