661005100157 has 2 divisors, whose sum is σ = 661005100158. Its totient is φ = 661005100156.

The previous prime is 661005100141. The next prime is 661005100183. The reversal of 661005100157 is 751001500166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 656835686116 + 4169414041 = 810454^2 + 64571^2 .

It is a cyclic number.

It is not a de Polignac number, because 661005100157 - 2⁴ = 661005100141 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661005105157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330502550078 + 330502550079.

It is an arithmetic number, because the mean of its divisors is an integer number (330502550079).

Almost surely, 2^661005100157 is an apocalyptic number.

It is an amenable number.

661005100157 is a deficient number, since it is larger than the sum of its proper divisors (1).

661005100157 is an equidigital number, since it uses as much as digits as its factorization.

661005100157 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6300, while the sum is 32.

The spelling of 661005100157 in words is "six hundred sixty-one billion, five million, one hundred thousand, one hundred fifty-seven".