21543737889351 has 4 divisors (see below), whose sum is σ = 28724983852472. Its totient is φ = 14362491926232.

The previous prime is 21543737889283. The next prime is 21543737889361. The reversal of 21543737889351 is 15398873734512.

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

It is not a de Polignac number, because 21543737889351 - 2²² = 21543733695047 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 (21543737889361) 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, 3590622981556 + ... + 3590622981561.

It is an arithmetic number, because the mean of its divisors is an integer number (7181245963118).

Almost surely, 2^{21543737889351} is an apocalyptic number.

21543737889351 is a deficient number, since it is larger than the sum of its proper divisors (7181245963121).

21543737889351 is an equidigital number, since it uses as much as digits as its factorization.

21543737889351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7181245963120.

The product of its digits is 152409600, while the sum is 66.

The spelling of 21543737889351 in words is "twenty-one trillion, five hundred forty-three billion, seven hundred thirty-seven million, eight hundred eighty-nine thousand, three hundred fifty-one".