21065256012 has 48 divisors (see below), whose sum is σ = 50537217024. Its totient is φ = 6825168000.

The previous prime is 21065255989. The next prime is 21065256013.

21065256012 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×21065256012² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21065256013) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 54337 + ... + 212327.

It is an arithmetic number, because the mean of its divisors is an integer number (1052858688).

Almost surely, 2^21065256012 is an apocalyptic number.

It is an amenable number.

21065256012 is an abundant number, since it is smaller than the sum of its proper divisors (29471961012).

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

21065256012 is a wasteful number, since it uses less digits than its factorization.

21065256012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158310 (or 158308 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The spelling of 21065256012 in words is "twenty-one billion, sixty-five million, two hundred fifty-six thousand, twelve".