661335061001 has 2 divisors, whose sum is σ = 661335061002. Its totient is φ = 661335061000.

The previous prime is 661335060943. The next prime is 661335061027. The reversal of 661335061001 is 100160533166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 644325684601 + 17009376400 = 802699^2 + 130420^2 .

It is a cyclic number.

It is not a de Polignac number, because 661335061001 - 2⁶ = 661335060937 is a prime.

It is a super-2 number, since 2×661335061001² (a number of 24 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (661335061031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330667530500 + 330667530501.

It is an arithmetic number, because the mean of its divisors is an integer number (330667530501).

Almost surely, 2^661335061001 is an apocalyptic number.

It is an amenable number.

661335061001 is a deficient number, since it is larger than the sum of its proper divisors (1).

661335061001 is an equidigital number, since it uses as much as digits as its factorization.

661335061001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9720, while the sum is 32.

Adding to 661335061001 its reverse (100160533166), we get a palindrome (761495594167).

The spelling of 661335061001 in words is "six hundred sixty-one billion, three hundred thirty-five million, sixty-one thousand, one".