21705234758 has 8 divisors (see below), whose sum is σ = 32562163920. Its totient is φ = 10851180120.

The previous prime is 21705234739. The next prime is 21705234767. The reversal of 21705234758 is 85743250712.

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

It is a super-2 number, since 2×21705234758² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 699653 + ... + 730016.

It is an arithmetic number, because the mean of its divisors is an integer number (4070270490).

Almost surely, 2^21705234758 is an apocalyptic number.

21705234758 is a deficient number, since it is larger than the sum of its proper divisors (10856929162).

21705234758 is a wasteful number, since it uses less digits than its factorization.

21705234758 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1437262.

The product of its (nonzero) digits is 470400, while the sum is 44.

The spelling of 21705234758 in words is "twenty-one billion, seven hundred five million, two hundred thirty-four thousand, seven hundred fifty-eight".