1801971265657 has 2 divisors, whose sum is σ = 1801971265658. Its totient is φ = 1801971265656.

The previous prime is 1801971265609. The next prime is 1801971265669. The reversal of 1801971265657 is 7565621791081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1128462168681 + 673509096976 = 1062291^2 + 820676^2 .

It is a cyclic number.

It is not a de Polignac number, because 1801971265657 - 2³⁵ = 1767611527289 is a prime.

It is not a weakly prime, because it can be changed into another prime (1801971265057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 900985632828 + 900985632829.

It is an arithmetic number, because the mean of its divisors is an integer number (900985632829).

Almost surely, 2^{1801971265657} is an apocalyptic number.

It is an amenable number.

1801971265657 is a deficient number, since it is larger than the sum of its proper divisors (1).

1801971265657 is an equidigital number, since it uses as much as digits as its factorization.

1801971265657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6350400, while the sum is 58.

The spelling of 1801971265657 in words is "one trillion, eight hundred one billion, nine hundred seventy-one million, two hundred sixty-five thousand, six hundred fifty-seven".