21142042043 has 4 divisors (see below), whose sum is σ = 21152992728. Its totient is φ = 21131091360.

The previous prime is 21142042039. The next prime is 21142042073. The reversal of 21142042043 is 34024024112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21142042043 - 2² = 21142042039 is a prime.

It is a super-2 number, since 2×21142042043² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21142042013) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5472446 + ... + 5476307.

It is an arithmetic number, because the mean of its divisors is an integer number (5288248182).

Almost surely, 2^21142042043 is an apocalyptic number.

21142042043 is a deficient number, since it is larger than the sum of its proper divisors (10950685).

21142042043 is a wasteful number, since it uses less digits than its factorization.

21142042043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10950684.

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21142042043 its reverse (34024024112), we get a palindrome (55166066155).

The spelling of 21142042043 in words is "twenty-one billion, one hundred forty-two million, forty-two thousand, forty-three".