21187303307 has 4 divisors (see below), whose sum is σ = 21870764736. Its totient is φ = 20503841880.

The previous prime is 21187303297. The next prime is 21187303309. The reversal of 21187303307 is 70330378112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21187303307 - 2³² = 16892336011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21187303309) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 341730668 + ... + 341730729.

It is an arithmetic number, because the mean of its divisors is an integer number (5467691184).

Almost surely, 2^21187303307 is an apocalyptic number.

21187303307 is a deficient number, since it is larger than the sum of its proper divisors (683461429).

21187303307 is an equidigital number, since it uses as much as digits as its factorization.

21187303307 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 683461428.

The product of its (nonzero) digits is 21168, while the sum is 35.

The spelling of 21187303307 in words is "twenty-one billion, one hundred eighty-seven million, three hundred three thousand, three hundred seven".