21217438793712 has 80 divisors (see below), whose sum is σ = 62669093921280. Its totient is φ = 6059499714816.

The previous prime is 21217438793669. The next prime is 21217438793713. The reversal of 21217438793712 is 21739783471212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21217438793713) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12898308 + ... + 14449955.

It is an arithmetic number, because the mean of its divisors is an integer number (783363674016).

Almost surely, 2^{21217438793712} is an apocalyptic number.

It is an amenable number.

21217438793712 is an abundant number, since it is smaller than the sum of its proper divisors (41451655127568).

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

21217438793712 is a wasteful number, since it uses less digits than its factorization.

21217438793712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27350590 (or 27350584 counting only the distinct ones).

The product of its digits is 7112448, while the sum is 57.

The spelling of 21217438793712 in words is "twenty-one trillion, two hundred seventeen billion, four hundred thirty-eight million, seven hundred ninety-three thousand, seven hundred twelve".