21586879 has 2 divisors, whose sum is σ = 21586880. Its totient is φ = 21586878.

The previous prime is 21586867. The next prime is 21586891. The reversal of 21586879 is 97868512.

It is a balanced prime because it is at equal distance from previous prime (21586867) and next prime (21586891).

It is a cyclic number.

It is not a de Polignac number, because 21586879 - 2¹⁵ = 21554111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21586849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10793439 + 10793440.

It is an arithmetic number, because the mean of its divisors is an integer number (10793440).

Almost surely, 2^21586879 is an apocalyptic number.

21586879 is a deficient number, since it is larger than the sum of its proper divisors (1).

21586879 is an equidigital number, since it uses as much as digits as its factorization.

21586879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 241920, while the sum is 46.

The square root of 21586879 is about 4646.1682061673. The cubic root of 21586879 is about 278.4389275880.

The spelling of 21586879 in words is "twenty-one million, five hundred eighty-six thousand, eight hundred seventy-nine".