21152210261543 has 4 divisors (see below), whose sum is σ = 21152490457968. Its totient is φ = 21151930065120.

The previous prime is 21152210261461. The next prime is 21152210261627. The reversal of 21152210261543 is 34516201225112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21152210261543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21152210264543) 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, 139984946 + ... + 140135967.

It is an arithmetic number, because the mean of its divisors is an integer number (5288122614492).

Almost surely, 2^{21152210261543} is an apocalyptic number.

21152210261543 is a deficient number, since it is larger than the sum of its proper divisors (280196425).

21152210261543 is an equidigital number, since it uses as much as digits as its factorization.

21152210261543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280196424.

The product of its (nonzero) digits is 28800, while the sum is 35.

Adding to 21152210261543 its reverse (34516201225112), we get a palindrome (55668411486655).

The spelling of 21152210261543 in words is "twenty-one trillion, one hundred fifty-two billion, two hundred ten million, two hundred sixty-one thousand, five hundred forty-three".