21645717101753 has 2 divisors, whose sum is σ = 21645717101754. Its totient is φ = 21645717101752.

The previous prime is 21645717101689. The next prime is 21645717101807. The reversal of 21645717101753 is 35710171754612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12024721358224 + 9620995743529 = 3467668^2 + 3101773^2 .

It is a cyclic number.

It is not a de Polignac number, because 21645717101753 - 2⁶ = 21645717101689 is a prime.

It is not a weakly prime, because it can be changed into another prime (21645717101153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10822858550876 + 10822858550877.

It is an arithmetic number, because the mean of its divisors is an integer number (10822858550877).

Almost surely, 2^{21645717101753} is an apocalyptic number.

It is an amenable number.

21645717101753 is a deficient number, since it is larger than the sum of its proper divisors (1).

21645717101753 is an equidigital number, since it uses as much as digits as its factorization.

21645717101753 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1234800, while the sum is 50.

The spelling of 21645717101753 in words is "twenty-one trillion, six hundred forty-five billion, seven hundred seventeen million, one hundred one thousand, seven hundred fifty-three".