1645300726081 has 2 divisors, whose sum is σ = 1645300726082. Its totient is φ = 1645300726080.

The previous prime is 1645300726079. The next prime is 1645300726133. The reversal of 1645300726081 is 1806270035461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1412807995456 + 232492730625 = 1188616^2 + 482175^2 .

It is a cyclic number.

It is not a de Polignac number, because 1645300726081 - 2¹ = 1645300726079 is a prime.

It is a super-2 number, since 2×1645300726081² (a number of 25 digits) contains 22 as substring.

Together with 1645300726079, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1645300726021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822650363040 + 822650363041.

It is an arithmetic number, because the mean of its divisors is an integer number (822650363041).

Almost surely, 2^{1645300726081} is an apocalyptic number.

It is an amenable number.

1645300726081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1645300726081 is an equidigital number, since it uses as much as digits as its factorization.

1645300726081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 241920, while the sum is 43.

The spelling of 1645300726081 in words is "one trillion, six hundred forty-five billion, three hundred million, seven hundred twenty-six thousand, eighty-one".