21542431105 has 16 divisors (see below), whose sum is σ = 27955952640. Its totient is φ = 15841683648.

The previous prime is 21542431087. The next prime is 21542431117. The reversal of 21542431105 is 50113424512.

It is a cyclic number.

It is not a de Polignac number, because 21542431105 - 2⁷ = 21542430977 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 677817 + ... + 708886.

It is an arithmetic number, because the mean of its divisors is an integer number (1747247040).

Almost surely, 2^21542431105 is an apocalyptic number.

It is an amenable number.

21542431105 is a deficient number, since it is larger than the sum of its proper divisors (6413521535).

21542431105 is a wasteful number, since it uses less digits than its factorization.

21542431105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1386960.

The product of its (nonzero) digits is 4800, while the sum is 28.

Adding to 21542431105 its reverse (50113424512), we get a palindrome (71655855617).

The spelling of 21542431105 in words is "twenty-one billion, five hundred forty-two million, four hundred thirty-one thousand, one hundred five".