21531054242 has 16 divisors (see below), whose sum is σ = 32630677632. Its totient is φ = 10654361040.

The previous prime is 21531054241. The next prime is 21531054301. The reversal of 21531054242 is 24245013512.

It is not an unprimeable number, because it can be changed into a prime (21531054241) 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, 169223 + ... + 267765.

It is an arithmetic number, because the mean of its divisors is an integer number (2039417352).

Almost surely, 2^21531054242 is an apocalyptic number.

21531054242 is a deficient number, since it is larger than the sum of its proper divisors (11099623390).

21531054242 is a wasteful number, since it uses less digits than its factorization.

21531054242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99673.

The product of its (nonzero) digits is 9600, while the sum is 29.

Adding to 21531054242 its reverse (24245013512), we get a palindrome (45776067754).

The spelling of 21531054242 in words is "twenty-one billion, five hundred thirty-one million, fifty-four thousand, two hundred forty-two".