661362100109 has 2 divisors, whose sum is σ = 661362100110. Its totient is φ = 661362100108.

The previous prime is 661362100097. The next prime is 661362100187. The reversal of 661362100109 is 901001263166.

661362100109 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 638257188100 + 23104912009 = 798910^2 + 152003^2 .

It is a cyclic number.

It is not a de Polignac number, because 661362100109 - 2¹⁶ = 661362034573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661362105109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330681050054 + 330681050055.

It is an arithmetic number, because the mean of its divisors is an integer number (330681050055).

Almost surely, 2^661362100109 is an apocalyptic number.

It is an amenable number.

661362100109 is a deficient number, since it is larger than the sum of its proper divisors (1).

661362100109 is an equidigital number, since it uses as much as digits as its factorization.

661362100109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 35.

The spelling of 661362100109 in words is "six hundred sixty-one billion, three hundred sixty-two million, one hundred thousand, one hundred nine".