21765534441 has 64 divisors (see below), whose sum is σ = 34367047680. Its totient is φ = 11997849600.

The previous prime is 21765534421. The next prime is 21765534451. The reversal of 21765534441 is 14443556712.

It is not a de Polignac number, because 21765534441 - 2⁶ = 21765534377 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21765534393 and 21765534402.

It is not an unprimeable number, because it can be changed into a prime (21765534421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 13783590 + ... + 13785168.

It is an arithmetic number, because the mean of its divisors is an integer number (536985120).

Almost surely, 2^21765534441 is an apocalyptic number.

21765534441 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21765534441 is a deficient number, since it is larger than the sum of its proper divisors (12601513239).

21765534441 is a wasteful number, since it uses less digits than its factorization.

21765534441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1854.

The product of its digits is 403200, while the sum is 42.

The spelling of 21765534441 in words is "twenty-one billion, seven hundred sixty-five million, five hundred thirty-four thousand, four hundred forty-one".