21745705336456 has 128 divisors (see below), whose sum is σ = 42556989530880. Its totient is φ = 10409247830016.

The previous prime is 21745705336447. The next prime is 21745705336501. The reversal of 21745705336456 is 65463350754712.

It is a self number, because there is not a number n which added to its sum of digits gives 21745705336456.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5426927205 + ... + 5426931211.

It is an arithmetic number, because the mean of its divisors is an integer number (332476480710).

Almost surely, 2^{21745705336456} is an apocalyptic number.

It is an amenable number.

21745705336456 is a deficient number, since it is larger than the sum of its proper divisors (20811284194424).

21745705336456 is a wasteful number, since it uses less digits than its factorization.

21745705336456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5423 (or 5419 counting only the distinct ones).

The product of its (nonzero) digits is 63504000, while the sum is 58.

The spelling of 21745705336456 in words is "twenty-one trillion, seven hundred forty-five billion, seven hundred five million, three hundred thirty-six thousand, four hundred fifty-six".