21288446723256 has 32 divisors (see below), whose sum is σ = 53221705610640. Its totient is φ = 7096070400768.

The previous prime is 21288446723251. The next prime is 21288446723267. The reversal of 21288446723256 is 65232764488212.

It is a self number, because there is not a number n which added to its sum of digits gives 21288446723256.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21288446723251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2671381 + ... + 7050756.

Almost surely, 2^{21288446723256} is an apocalyptic number.

It is an amenable number.

21288446723256 is an abundant number, since it is smaller than the sum of its proper divisors (31933258887384).

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

21288446723256 is a wasteful number, since it uses less digits than its factorization.

21288446723256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9813383 (or 9813379 counting only the distinct ones).

The product of its digits is 61931520, while the sum is 60.

The spelling of 21288446723256 in words is "twenty-one trillion, two hundred eighty-eight billion, four hundred forty-six million, seven hundred twenty-three thousand, two hundred fifty-six".