21259679 has 12 divisors (see below), whose sum is σ = 24837408. Its totient is φ = 18144000.

The previous prime is 21259669. The next prime is 21259681. The reversal of 21259679 is 97695212.

It is not a de Polignac number, because 21259679 - 2⁴ = 21259663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21259669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12479 + ... + 14079.

It is an arithmetic number, because the mean of its divisors is an integer number (2069784).

Almost surely, 2^21259679 is an apocalyptic number.

21259679 is a deficient number, since it is larger than the sum of its proper divisors (3577729).

21259679 is a wasteful number, since it uses less digits than its factorization.

21259679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1886 (or 1879 counting only the distinct ones).

The product of its digits is 68040, while the sum is 41.

The square root of 21259679 is about 4610.8219440790. The cubic root of 21259679 is about 277.0249600641.

The spelling of 21259679 in words is "twenty-one million, two hundred fifty-nine thousand, six hundred seventy-nine".