21825638607817 has 24 divisors (see below), whose sum is σ = 24308784783360. Its totient is φ = 19578551863200.

The previous prime is 21825638607803. The next prime is 21825638607823. The reversal of 21825638607817 is 71870683652812.

It is a de Polignac number, because none of the positive numbers 2^k-21825638607817 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21825638607317) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6921784 + ... + 9568822.

It is an arithmetic number, because the mean of its divisors is an integer number (1012866032640).

Almost surely, 2^{21825638607817} is an apocalyptic number.

It is an amenable number.

21825638607817 is a deficient number, since it is larger than the sum of its proper divisors (2483146175543).

21825638607817 is a wasteful number, since it uses less digits than its factorization.

21825638607817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2647965 (or 2647954 counting only the distinct ones).

The product of its (nonzero) digits is 54190080, while the sum is 64.

The spelling of 21825638607817 in words is "twenty-one trillion, eight hundred twenty-five billion, six hundred thirty-eight million, six hundred seven thousand, eight hundred seventeen".