21034042542 has 12 divisors (see below), whose sum is σ = 45573758880. Its totient is φ = 7011347508.

The previous prime is 21034042529. The next prime is 21034042571. The reversal of 21034042542 is 24524043012.

21034042542 is a `hidden beast` number, since 2 + 1 + 0 + 3 + 404 + 254 + 2 = 666.

It is a super-3 number, since 3×21034042542³ (a number of 32 digits) contains 333 as substring.

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 5 ways as a sum of consecutive naturals, for example, 584278942 + ... + 584278977.

It is an arithmetic number, because the mean of its divisors is an integer number (3797813240).

Almost surely, 2^21034042542 is an apocalyptic number.

21034042542 is an abundant number, since it is smaller than the sum of its proper divisors (24539716338).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21034042542 is a wasteful number, since it uses less digits than its factorization.

21034042542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1168557927 (or 1168557924 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 27.

Adding to 21034042542 its reverse (24524043012), we get a palindrome (45558085554).

The spelling of 21034042542 in words is "twenty-one billion, thirty-four million, forty-two thousand, five hundred forty-two".