21656105165342 has 16 divisors (see below), whose sum is σ = 32499972029952. Its totient is φ = 10822781596440.

The previous prime is 21656105165327. The next prime is 21656105165353. The reversal of 21656105165342 is 24356150165612.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 111761513 + ... + 111955115.

It is an arithmetic number, because the mean of its divisors is an integer number (2031248251872).

Almost surely, 2^{21656105165342} is an apocalyptic number.

21656105165342 is a deficient number, since it is larger than the sum of its proper divisors (10843866864610).

21656105165342 is a wasteful number, since it uses less digits than its factorization.

21656105165342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220543.

The product of its (nonzero) digits is 1296000, while the sum is 47.

The spelling of 21656105165342 in words is "twenty-one trillion, six hundred fifty-six billion, one hundred five million, one hundred sixty-five thousand, three hundred forty-two".