21645059331 has 16 divisors (see below), whose sum is σ = 34718892800. Its totient is φ = 11717625888.

The previous prime is 21645059299. The next prime is 21645059377. The reversal of 21645059331 is 13395054612.

It is not a de Polignac number, because 21645059331 - 2⁵ = 21645059299 is a prime.

It is a super-2 number, since 2×21645059331² (a number of 21 digits) contains 22 as substring.

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 21645059331.

It is not an unprimeable number, because it can be changed into a prime (21645059231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27123736 + ... + 27124533.

It is an arithmetic number, because the mean of its divisors is an integer number (2169930800).

Almost surely, 2^21645059331 is an apocalyptic number.

21645059331 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21645059331 is a deficient number, since it is larger than the sum of its proper divisors (13073833469).

21645059331 is a wasteful number, since it uses less digits than its factorization.

21645059331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54248298.

The product of its (nonzero) digits is 97200, while the sum is 39.

The spelling of 21645059331 in words is "twenty-one billion, six hundred forty-five million, fifty-nine thousand, three hundred thirty-one".