21187008027 has 8 divisors (see below), whose sum is σ = 31388160080. Its totient is φ = 14124672000.

The previous prime is 21187008019. The next prime is 21187008041. The reversal of 21187008027 is 72080078112.

It is a happy number.

It is not a de Polignac number, because 21187008027 - 2³ = 21187008019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21187007982 and 21187008000.

It is not an unprimeable number, because it can be changed into a prime (21187008077) 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, 392351974 + ... + 392352027.

It is an arithmetic number, because the mean of its divisors is an integer number (3923520010).

Almost surely, 2^21187008027 is an apocalyptic number.

21187008027 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21187008027 is a deficient number, since it is larger than the sum of its proper divisors (10201152053).

21187008027 is an equidigital number, since it uses as much as digits as its factorization.

21187008027 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 784704010 (or 784704004 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 36.

The spelling of 21187008027 in words is "twenty-one billion, one hundred eighty-seven million, eight thousand, twenty-seven".