21508748307 has 24 divisors (see below), whose sum is σ = 32238505728. Its totient is φ = 13808415600.

The previous prime is 21508748269. The next prime is 21508748377. The reversal of 21508748307 is 70384780512.

It is not a de Polignac number, because 21508748307 - 2¹⁰ = 21508747283 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21508748377) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 363919 + ... + 418872.

It is an arithmetic number, because the mean of its divisors is an integer number (1343271072).

Almost surely, 2^21508748307 is an apocalyptic number.

21508748307 is a deficient number, since it is larger than the sum of its proper divisors (10729757421).

21508748307 is a wasteful number, since it uses less digits than its factorization.

21508748307 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782911 (or 782908 counting only the distinct ones).

The product of its (nonzero) digits is 376320, while the sum is 45.

The spelling of 21508748307 in words is "twenty-one billion, five hundred eight million, seven hundred forty-eight thousand, three hundred seven".