21550433551243 has 8 divisors (see below), whose sum is σ = 21824270343680. Its totient is φ = 21276622921320.

The previous prime is 21550433551201. The next prime is 21550433551379. The reversal of 21550433551243 is 34215533405512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21550433551243 - 2⁹ = 21550433550731 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21550433551243.

It is not an unprimeable number, because it can be changed into a prime (21550433551643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4880073 + ... + 8180218.

It is an arithmetic number, because the mean of its divisors is an integer number (2728033792960).

Almost surely, 2^{21550433551243} is an apocalyptic number.

21550433551243 is a deficient number, since it is larger than the sum of its proper divisors (273836792437).

21550433551243 is a wasteful number, since it uses less digits than its factorization.

21550433551243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13081257.

The product of its (nonzero) digits is 1080000, while the sum is 43.

Adding to 21550433551243 its reverse (34215533405512), we get a palindrome (55765966956755).

The spelling of 21550433551243 in words is "twenty-one trillion, five hundred fifty billion, four hundred thirty-three million, five hundred fifty-one thousand, two hundred forty-three".