21116544373 has 4 divisors (see below), whose sum is σ = 22358694060. Its totient is φ = 19874394688.

The previous prime is 21116544331. The next prime is 21116544377. The reversal of 21116544373 is 37344561112.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 14738445604 + 6378098769 = 121402^2 + 79863^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21116544373 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 (21116544377) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 621074818 + ... + 621074851.

It is an arithmetic number, because the mean of its divisors is an integer number (5589673515).

Almost surely, 2^21116544373 is an apocalyptic number.

It is an amenable number.

21116544373 is a deficient number, since it is larger than the sum of its proper divisors (1242149687).

21116544373 is a wasteful number, since it uses less digits than its factorization.

21116544373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1242149686.

The product of its digits is 60480, while the sum is 37.

The spelling of 21116544373 in words is "twenty-one billion, one hundred sixteen million, five hundred forty-four thousand, three hundred seventy-three".