21144208985 has 8 divisors (see below), whose sum is σ = 25694229120. Its totient is φ = 16701248304.

The previous prime is 21144208979. The next prime is 21144209039. The reversal of 21144208985 is 58980244112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21144208985 - 2³⁴ = 3964339801 is a prime.

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, 26764427 + ... + 26765216.

It is an arithmetic number, because the mean of its divisors is an integer number (3211778640).

Almost surely, 2^21144208985 is an apocalyptic number.

It is an amenable number.

21144208985 is a deficient number, since it is larger than the sum of its proper divisors (4550020135).

21144208985 is an equidigital number, since it uses as much as digits as its factorization.

21144208985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53529727.

The product of its (nonzero) digits is 184320, while the sum is 44.

The spelling of 21144208985 in words is "twenty-one billion, one hundred forty-four million, two hundred eight thousand, nine hundred eighty-five".