21418726659 has 16 divisors (see below), whose sum is σ = 31169357184. Its totient is φ = 12974860800.

The previous prime is 21418726621. The next prime is 21418726661. The reversal of 21418726659 is 95662781412.

It is not a de Polignac number, because 21418726659 - 2⁷ = 21418726531 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21418726669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 83857 + ... + 223314.

It is an arithmetic number, because the mean of its divisors is an integer number (1948084824).

Almost surely, 2^21418726659 is an apocalyptic number.

21418726659 is a deficient number, since it is larger than the sum of its proper divisors (9750630525).

21418726659 is a wasteful number, since it uses less digits than its factorization.

21418726659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309298.

The product of its digits is 1451520, while the sum is 51.

The spelling of 21418726659 in words is "twenty-one billion, four hundred eighteen million, seven hundred twenty-six thousand, six hundred fifty-nine".