21140042542 has 16 divisors (see below), whose sum is σ = 33382713600. Its totient is φ = 10012594680.

The previous prime is 21140042503. The next prime is 21140042563. The reversal of 21140042542 is 24524004112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 391867 + ... + 442537.

It is an arithmetic number, because the mean of its divisors is an integer number (2086419600).

Almost surely, 2^21140042542 is an apocalyptic number.

21140042542 is a deficient number, since it is larger than the sum of its proper divisors (12242671058).

21140042542 is a wasteful number, since it uses less digits than its factorization.

21140042542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61671.

The product of its (nonzero) digits is 2560, while the sum is 25.

Adding to 21140042542 its reverse (24524004112), we get a palindrome (45664046654).

The spelling of 21140042542 in words is "twenty-one billion, one hundred forty million, forty-two thousand, five hundred forty-two".