21681010045 has 8 divisors (see below), whose sum is σ = 26018436096. Its totient is φ = 17343992016.

The previous prime is 21681010003. The next prime is 21681010063. The reversal of 21681010045 is 54001018612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21681010045 - 2²⁷ = 21546792317 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21681009995 and 21681010022.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 30564 + ... + 210466.

It is an arithmetic number, because the mean of its divisors is an integer number (3252304512).

Almost surely, 2^21681010045 is an apocalyptic number.

It is an amenable number.

21681010045 is a deficient number, since it is larger than the sum of its proper divisors (4337426051).

21681010045 is a wasteful number, since it uses less digits than its factorization.

21681010045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204011.

The product of its (nonzero) digits is 1920, while the sum is 28.

Adding to 21681010045 its reverse (54001018612), we get a palindrome (75682028657).

The spelling of 21681010045 in words is "twenty-one billion, six hundred eighty-one million, ten thousand, forty-five".