21645132360 has 64 divisors (see below), whose sum is σ = 68755132800. Its totient is φ = 5432503296.

The previous prime is 21645132347. The next prime is 21645132413. The reversal of 21645132360 is 6323154612.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5303140 + ... + 5307219.

It is an arithmetic number, because the mean of its divisors is an integer number (1074298950).

Almost surely, 2^21645132360 is an apocalyptic number.

21645132360 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21645132360 is an abundant number, since it is smaller than the sum of its proper divisors (47110000440).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21645132360 is a wasteful number, since it uses less digits than its factorization.

21645132360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10610390 (or 10610386 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 33.

Adding to 21645132360 its reverse (6323154612), we get a palindrome (27968286972).

The spelling of 21645132360 in words is "twenty-one billion, six hundred forty-five million, one hundred thirty-two thousand, three hundred sixty".