21524494609 has 4 divisors (see below), whose sum is σ = 21536303616. Its totient is φ = 21512685604.

The previous prime is 21524494591. The next prime is 21524494613. The reversal of 21524494609 is 90649442512.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21524494609 - 2³³ = 12934560017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21524494619) 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, 5901769 + ... + 5905414.

It is an arithmetic number, because the mean of its divisors is an integer number (5384075904).

Almost surely, 2^21524494609 is an apocalyptic number.

It is an amenable number.

21524494609 is a deficient number, since it is larger than the sum of its proper divisors (11809007).

21524494609 is a wasteful number, since it uses less digits than its factorization.

21524494609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11809006.

The product of its (nonzero) digits is 622080, while the sum is 46.

The spelling of 21524494609 in words is "twenty-one billion, five hundred twenty-four million, four hundred ninety-four thousand, six hundred nine".