21601703986 has 16 divisors (see below), whose sum is σ = 32770961208. Its totient is φ = 10678528000.

The previous prime is 21601703951. The next prime is 21601704127. The reversal of 21601703986 is 68930710612.

It can be written as a sum of positive squares in 4 ways, for example, as 21393450225 + 208253761 = 146265^2 + 14431^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28555 + ... + 209806.

Almost surely, 2^21601703986 is an apocalyptic number.

21601703986 is a deficient number, since it is larger than the sum of its proper divisors (11169257222).

21601703986 is a wasteful number, since it uses less digits than its factorization.

21601703986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238877.

The product of its (nonzero) digits is 108864, while the sum is 43.

The spelling of 21601703986 in words is "twenty-one billion, six hundred one million, seven hundred three thousand, nine hundred eighty-six".