21489686826 has 16 divisors (see below), whose sum is σ = 42991280064. Its totient is φ = 7161244544.

The previous prime is 21489686819. The next prime is 21489686833. The reversal of 21489686826 is 62868698412.

It is an interprime number because it is at equal distance from previous prime (21489686819) and next prime (21489686833).

It is a self number, because there is not a number n which added to its sum of digits gives 21489686826.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 472551 + ... + 516026.

It is an arithmetic number, because the mean of its divisors is an integer number (2686955004).

Almost surely, 2^21489686826 is an apocalyptic number.

21489686826 is an abundant number, since it is smaller than the sum of its proper divisors (21501593238).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21489686826 is a wasteful number, since it uses less digits than its factorization.

21489686826 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 992205.

The product of its digits is 15925248, while the sum is 60.

The spelling of 21489686826 in words is "twenty-one billion, four hundred eighty-nine million, six hundred eighty-six thousand, eight hundred twenty-six".