21768708353 has 16 divisors (see below), whose sum is σ = 25641930624. Its totient is φ = 18089930880.

The previous prime is 21768708347. The next prime is 21768708361. The reversal of 21768708353 is 35380786712.

It is a happy number.

It is not a de Polignac number, because 21768708353 - 2³⁰ = 20694966529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21768708343) 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, 76775 + ... + 222332.

It is an arithmetic number, because the mean of its divisors is an integer number (1602620664).

Almost surely, 2^21768708353 is an apocalyptic number.

It is an amenable number.

21768708353 is a deficient number, since it is larger than the sum of its proper divisors (3873222271).

21768708353 is a wasteful number, since it uses less digits than its factorization.

21768708353 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299432.

The product of its (nonzero) digits is 1693440, while the sum is 50.

The spelling of 21768708353 in words is "twenty-one billion, seven hundred sixty-eight million, seven hundred eight thousand, three hundred fifty-three".