165220626543491 has 2 divisors, whose sum is σ = 165220626543492. Its totient is φ = 165220626543490.

The previous prime is 165220626543463. The next prime is 165220626543649. The reversal of 165220626543491 is 194345626022561.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 165220626543491 - 2⁴⁶ = 94851882365827 is a prime.

It is a super-2 number, since 2×165220626543491² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (165220626543431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82610313271745 + 82610313271746.

It is an arithmetic number, because the mean of its divisors is an integer number (82610313271746).

Almost surely, 2^{165220626543491} is an apocalyptic number.

165220626543491 is a deficient number, since it is larger than the sum of its proper divisors (1).

165220626543491 is an equidigital number, since it uses as much as digits as its factorization.

165220626543491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18662400, while the sum is 56.

The spelling of 165220626543491 in words is "one hundred sixty-five trillion, two hundred twenty billion, six hundred twenty-six million, five hundred forty-three thousand, four hundred ninety-one".