1491422826217 has 2 divisors, whose sum is σ = 1491422826218. Its totient is φ = 1491422826216.

The previous prime is 1491422826191. The next prime is 1491422826227. The reversal of 1491422826217 is 7126282241941.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1351555054096 + 139867772121 = 1162564^2 + 373989^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1491422826217 is a prime.

It is a super-2 number, since 2×1491422826217² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1491422826227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 745711413108 + 745711413109.

It is an arithmetic number, because the mean of its divisors is an integer number (745711413109).

Almost surely, 2^{1491422826217} is an apocalyptic number.

It is an amenable number.

1491422826217 is a deficient number, since it is larger than the sum of its proper divisors (1).

1491422826217 is an equidigital number, since it uses as much as digits as its factorization.

1491422826217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 774144, while the sum is 49.

The spelling of 1491422826217 in words is "one trillion, four hundred ninety-one billion, four hundred twenty-two million, eight hundred twenty-six thousand, two hundred seventeen".