21256044520616 has 32 divisors (see below), whose sum is σ = 40228634759040. Its totient is φ = 10528413888768.

The previous prime is 21256044520603. The next prime is 21256044520649. The reversal of 21256044520616 is 61602544065212.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33806081 + ... + 34429103.

It is an arithmetic number, because the mean of its divisors is an integer number (1257144836220).

Almost surely, 2^{21256044520616} is an apocalyptic number.

It is an amenable number.

21256044520616 is a deficient number, since it is larger than the sum of its proper divisors (18972590238424).

21256044520616 is a wasteful number, since it uses less digits than its factorization.

21256044520616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 662993 (or 662989 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 44.

Adding to 21256044520616 its reverse (61602544065212), we get a palindrome (82858588585828).

The spelling of 21256044520616 in words is "twenty-one trillion, two hundred fifty-six billion, forty-four million, five hundred twenty thousand, six hundred sixteen".