21601703985 has 16 divisors (see below), whose sum is σ = 34641467520. Its totient is φ = 11494661760.

The previous prime is 21601703951. The next prime is 21601704127. The reversal of 21601703985 is 58930710612.

It is a de Polignac number, because none of the positive numbers 2^k-21601703985 is a prime.

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 15 ways as a sum of consecutive naturals, for example, 1633636 + ... + 1646805.

It is an arithmetic number, because the mean of its divisors is an integer number (2165091720).

Almost surely, 2^21601703985 is an apocalyptic number.

It is an amenable number.

21601703985 is a deficient number, since it is larger than the sum of its proper divisors (13039763535).

21601703985 is a wasteful number, since it uses less digits than its factorization.

21601703985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3280888.

The product of its (nonzero) digits is 90720, while the sum is 42.

The spelling of 21601703985 in words is "twenty-one billion, six hundred one million, seven hundred three thousand, nine hundred eighty-five".