21166371147689 has 2 divisors, whose sum is σ = 21166371147690. Its totient is φ = 21166371147688.

The previous prime is 21166371147659. The next prime is 21166371147697. The reversal of 21166371147689 is 98674117366112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19049733160000 + 2116637987689 = 4364600^2 + 1454867^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21166371147689 is a prime.

It is not a weakly prime, because it can be changed into another prime (21166371147659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10583185573844 + 10583185573845.

It is an arithmetic number, because the mean of its divisors is an integer number (10583185573845).

Almost surely, 2^{21166371147689} is an apocalyptic number.

It is an amenable number.

21166371147689 is a deficient number, since it is larger than the sum of its proper divisors (1).

21166371147689 is an equidigital number, since it uses as much as digits as its factorization.

21166371147689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18289152, while the sum is 62.

The spelling of 21166371147689 in words is "twenty-one trillion, one hundred sixty-six billion, three hundred seventy-one million, one hundred forty-seven thousand, six hundred eighty-nine".