21534015449 has 16 divisors (see below), whose sum is σ = 22379054544. Its totient is φ = 20704665600.

The previous prime is 21534015439. The next prime is 21534015457. The reversal of 21534015449 is 94451043512.

It can be written as a sum of positive squares in 8 ways, for example, as 95199049 + 21438816400 = 9757^2 + 146420^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21534015449 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21534015409) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5723729 + ... + 5727489.

It is an arithmetic number, because the mean of its divisors is an integer number (1398690909).

Almost surely, 2^21534015449 is an apocalyptic number.

It is an amenable number.

21534015449 is a deficient number, since it is larger than the sum of its proper divisors (845039095).

21534015449 is a wasteful number, since it uses less digits than its factorization.

21534015449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5788.

The product of its (nonzero) digits is 86400, while the sum is 38.

The spelling of 21534015449 in words is "twenty-one billion, five hundred thirty-four million, fifteen thousand, four hundred forty-nine".