21603220020043 has 4 divisors (see below), whose sum is σ = 21605322942808. Its totient is φ = 21601117097280.

The previous prime is 21603220020037. The next prime is 21603220020127. The reversal of 21603220020043 is 34002002230612.

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 21603220020043 - 2⁹ = 21603220019531 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21603220020013) 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, 1051445973 + ... + 1051466518.

It is an arithmetic number, because the mean of its divisors is an integer number (5401330735702).

Almost surely, 2^{21603220020043} is an apocalyptic number.

21603220020043 is a deficient number, since it is larger than the sum of its proper divisors (2102922765).

21603220020043 is a wasteful number, since it uses less digits than its factorization.

21603220020043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2102922764.

The product of its (nonzero) digits is 3456, while the sum is 25.

Adding to 21603220020043 its reverse (34002002230612), we get a palindrome (55605222250655).

The spelling of 21603220020043 in words is "twenty-one trillion, six hundred three billion, two hundred twenty million, twenty thousand, forty-three".