21306661526444 has 48 divisors (see below), whose sum is σ = 42701843627520. Its totient is φ = 9112476119040.

The previous prime is 21306661526431. The next prime is 21306661526471. The reversal of 21306661526444 is 44462516660312.

It is a happy number.

It is a super-2 number, since 2×21306661526444² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21306661526392 and 21306661526401.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27414569 + ... + 28181055.

It is an arithmetic number, because the mean of its divisors is an integer number (889621742240).

Almost surely, 2^{21306661526444} is an apocalyptic number.

It is an amenable number.

21306661526444 is an abundant number, since it is smaller than the sum of its proper divisors (21395182101076).

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

21306661526444 is a wasteful number, since it uses less digits than its factorization.

21306661526444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 768558 (or 768556 counting only the distinct ones).

The product of its (nonzero) digits is 4976640, while the sum is 50.

The spelling of 21306661526444 in words is "twenty-one trillion, three hundred six billion, six hundred sixty-one million, five hundred twenty-six thousand, four hundred forty-four".