21142242542 has 16 divisors (see below), whose sum is σ = 33712649712. Its totient is φ = 9909648000.

The previous prime is 21142242497. The next prime is 21142242581. The reversal of 21142242542 is 24524224112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1230173 + ... + 1247240.

It is an arithmetic number, because the mean of its divisors is an integer number (2107040607).

Almost surely, 2^21142242542 is an apocalyptic number.

21142242542 is a deficient number, since it is larger than the sum of its proper divisors (12570407170).

21142242542 is a wasteful number, since it uses less digits than its factorization.

21142242542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2477683.

The product of its digits is 10240, while the sum is 29.

Adding to 21142242542 its reverse (24524224112), we get a palindrome (45666466654).

The spelling of 21142242542 in words is "twenty-one billion, one hundred forty-two million, two hundred forty-two thousand, five hundred forty-two".