21705404032686 has 32 divisors (see below), whose sum is σ = 47702918504448. Its totient is φ = 6529384975040.

The previous prime is 21705404032633. The next prime is 21705404032691. The reversal of 21705404032686 is 68623040450712.

It is a super-2 number, since 2×21705404032686² (a number of 27 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 15 ways as a sum of consecutive naturals, for example, 1200245550 + ... + 1200263633.

It is an arithmetic number, because the mean of its divisors is an integer number (1490716203264).

Almost surely, 2^{21705404032686} is an apocalyptic number.

21705404032686 is an abundant number, since it is smaller than the sum of its proper divisors (25997514471762).

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

21705404032686 is a wasteful number, since it uses less digits than its factorization.

21705404032686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2400509336.

The product of its (nonzero) digits is 1935360, while the sum is 48.

The spelling of 21705404032686 in words is "twenty-one trillion, seven hundred five billion, four hundred four million, thirty-two thousand, six hundred eighty-six".