21661030363264 has 32 divisors (see below), whose sum is σ = 44544860835840. Its totient is φ = 10481143722240.

The previous prime is 21661030363213. The next prime is 21661030363283. The reversal of 21661030363264 is 46236303016612.

It is a tau number, because it is divible by the number of its divisors (32).

It is a self number, because there is not a number n which added to its sum of digits gives 21661030363264.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 2729460544 + ... + 2729468479.

It is an arithmetic number, because the mean of its divisors is an integer number (1392026901120).

Almost surely, 2^{21661030363264} is an apocalyptic number.

It is an amenable number.

21661030363264 is an abundant number, since it is smaller than the sum of its proper divisors (22883830472576).

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

21661030363264 is an equidigital number, since it uses as much as digits as its factorization.

21661030363264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5458929068 (or 5458929056 counting only the distinct ones).

The product of its (nonzero) digits is 559872, while the sum is 43.

Adding to 21661030363264 its reverse (46236303016612), we get a palindrome (67897333379876).

The spelling of 21661030363264 in words is "twenty-one trillion, six hundred sixty-one billion, thirty million, three hundred sixty-three thousand, two hundred sixty-four".