21985371827 has 12 divisors (see below), whose sum is σ = 23303072520. Its totient is φ = 20738776032.

The previous prime is 21985371799. The next prime is 21985371847. The reversal of 21985371827 is 72817358912.

It is not a de Polignac number, because 21985371827 - 2¹² = 21985367731 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21985371847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 46577 + ... + 214802.

It is an arithmetic number, because the mean of its divisors is an integer number (1941922710).

Almost surely, 2^21985371827 is an apocalyptic number.

21985371827 is a deficient number, since it is larger than the sum of its proper divisors (1317700693).

21985371827 is a wasteful number, since it uses less digits than its factorization.

21985371827 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261650 (or 261631 counting only the distinct ones).

The product of its digits is 1693440, while the sum is 53.

The spelling of 21985371827 in words is "twenty-one billion, nine hundred eighty-five million, three hundred seventy-one thousand, eight hundred twenty-seven".