21537613440066 has 8 divisors (see below), whose sum is σ = 43075226880144. Its totient is φ = 7179204480020.

The previous prime is 21537613440047. The next prime is 21537613440089. The reversal of 21537613440066 is 66004431673512.

It is a sphenic number, since it is the product of 3 distinct primes.

21537613440066 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 21537613439997 and 21537613440024.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1794801120000 + ... + 1794801120011.

It is an arithmetic number, because the mean of its divisors is an integer number (5384403360018).

Almost surely, 2^{21537613440066} is an apocalyptic number.

21537613440066 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21537613440066 is a wasteful number, since it uses less digits than its factorization.

21537613440066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3589602240016.

The product of its (nonzero) digits is 2177280, while the sum is 48.

The spelling of 21537613440066 in words is "twenty-one trillion, five hundred thirty-seven billion, six hundred thirteen million, four hundred forty thousand, sixty-six".