21524521747 has 8 divisors (see below), whose sum is σ = 22108179600. Its totient is φ = 20940964704.

The previous prime is 21524521727. The next prime is 21524521801. The reversal of 21524521747 is 74712542512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21524521747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21524521727) 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, 647529 + ... + 679957.

It is an arithmetic number, because the mean of its divisors is an integer number (2763522450).

Almost surely, 2^21524521747 is an apocalyptic number.

21524521747 is a deficient number, since it is larger than the sum of its proper divisors (583657853).

21524521747 is a wasteful number, since it uses less digits than its factorization.

21524521747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50405.

The product of its digits is 156800, while the sum is 40.

The spelling of 21524521747 in words is "twenty-one billion, five hundred twenty-four million, five hundred twenty-one thousand, seven hundred forty-seven".