21705040631 has 8 divisors (see below), whose sum is σ = 22459996800. Its totient is φ = 20953509120.

The previous prime is 21705040607. The next prime is 21705040639. The reversal of 21705040631 is 13604050712.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21705040631 is a prime.

It is a super-2 number, since 2×21705040631² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21705040594 and 21705040603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21705040639) 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 7 ways as a sum of consecutive naturals, for example, 843266 + ... + 868623.

It is an arithmetic number, because the mean of its divisors is an integer number (2807499600).

Almost surely, 2^21705040631 is an apocalyptic number.

21705040631 is a deficient number, since it is larger than the sum of its proper divisors (754956169).

21705040631 is a wasteful number, since it uses less digits than its factorization.

21705040631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1712329.

The product of its (nonzero) digits is 5040, while the sum is 29.

The spelling of 21705040631 in words is "twenty-one billion, seven hundred five million, forty thousand, six hundred thirty-one".