21041340043 has 4 divisors (see below), whose sum is σ = 21294850248. Its totient is φ = 20787829840.

The previous prime is 21041340041. The next prime is 21041340059. The reversal of 21041340043 is 34004314012.

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 21041340043 - 2¹ = 21041340041 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21041339996 and 21041340023.

It is not an unprimeable number, because it can be changed into a prime (21041340041) 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, 126754978 + ... + 126755143.

It is an arithmetic number, because the mean of its divisors is an integer number (5323712562).

Almost surely, 2^21041340043 is an apocalyptic number.

21041340043 is a deficient number, since it is larger than the sum of its proper divisors (253510205).

21041340043 is an equidigital number, since it uses as much as digits as its factorization.

21041340043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253510204.

The product of its (nonzero) digits is 1152, while the sum is 22.

Adding to 21041340043 its reverse (34004314012), we get a palindrome (55045654055).

The spelling of 21041340043 in words is "twenty-one billion, forty-one million, three hundred forty thousand, forty-three".