21680543726 has 16 divisors (see below), whose sum is σ = 32764265424. Its totient is φ = 10759334784.

The previous prime is 21680543723. The next prime is 21680543767. The reversal of 21680543726 is 62734508612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21680543723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 152345 + ... + 258011.

It is an arithmetic number, because the mean of its divisors is an integer number (2047766589).

Almost surely, 2^21680543726 is an apocalyptic number.

21680543726 is a deficient number, since it is larger than the sum of its proper divisors (11083721698).

21680543726 is a wasteful number, since it uses less digits than its factorization.

21680543726 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106435.

The product of its (nonzero) digits is 483840, while the sum is 44.

The spelling of 21680543726 in words is "twenty-one billion, six hundred eighty million, five hundred forty-three thousand, seven hundred twenty-six".