21706906459 has 48 divisors (see below), whose sum is σ = 27815854080. Its totient is φ = 16822753920.

The previous prime is 21706906457. The next prime is 21706906517. The reversal of 21706906459 is 95460960712.

It is a happy number.

It is not a de Polignac number, because 21706906459 - 2¹ = 21706906457 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (21706906451) 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 47 ways as a sum of consecutive naturals, for example, 2101702 + ... + 2112004.

It is an arithmetic number, because the mean of its divisors is an integer number (579496960).

Almost surely, 2^21706906459 is an apocalyptic number.

21706906459 is a deficient number, since it is larger than the sum of its proper divisors (6108947621).

21706906459 is a wasteful number, since it uses less digits than its factorization.

21706906459 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10440 (or 10433 counting only the distinct ones).

The product of its (nonzero) digits is 816480, while the sum is 49.

The spelling of 21706906459 in words is "twenty-one billion, seven hundred six million, nine hundred six thousand, four hundred fifty-nine".