21440542642 has 16 divisors (see below), whose sum is σ = 32228985600. Its totient is φ = 10697572800.

The previous prime is 21440542619. The next prime is 21440542649. The reversal of 21440542642 is 24624504412.

It is a junction number, because it is equal to n+sod(n) for n = 21440542598 and 21440542607.

It is not an unprimeable number, because it can be changed into a prime (21440542649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2009959 + ... + 2020597.

It is an arithmetic number, because the mean of its divisors is an integer number (2014311600).

Almost surely, 2^21440542642 is an apocalyptic number.

21440542642 is a deficient number, since it is larger than the sum of its proper divisors (10788442958).

21440542642 is a wasteful number, since it uses less digits than its factorization.

21440542642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12681.

The product of its (nonzero) digits is 61440, while the sum is 34.

The spelling of 21440542642 in words is "twenty-one billion, four hundred forty million, five hundred forty-two thousand, six hundred forty-two".