21707524507 has 4 divisors (see below), whose sum is σ = 21708914976. Its totient is φ = 21706134040.

The previous prime is 21707524469. The next prime is 21707524547. The reversal of 21707524507 is 70542570712.

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 21707524507 - 2²⁷ = 21573306779 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21707524507.

It is not an unprimeable number, because it can be changed into a prime (21707524547) 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 3 ways as a sum of consecutive naturals, for example, 671548 + ... + 703129.

It is an arithmetic number, because the mean of its divisors is an integer number (5427228744).

Almost surely, 2^21707524507 is an apocalyptic number.

21707524507 is a deficient number, since it is larger than the sum of its proper divisors (1390469).

21707524507 is a wasteful number, since it uses less digits than its factorization.

21707524507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1390468.

The product of its (nonzero) digits is 137200, while the sum is 40.

The spelling of 21707524507 in words is "twenty-one billion, seven hundred seven million, five hundred twenty-four thousand, five hundred seven".