661005625640093 has 2 divisors, whose sum is σ = 661005625640094. Its totient is φ = 661005625640092.

The previous prime is 661005625640083. The next prime is 661005625640131. The reversal of 661005625640093 is 390046526500166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 609149885245444 + 51855740394649 = 24680962^2 + 7201093^2 .

It is a cyclic number.

It is not a de Polignac number, because 661005625640093 - 2¹⁸ = 661005625377949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661005625640083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330502812820046 + 330502812820047.

It is an arithmetic number, because the mean of its divisors is an integer number (330502812820047).

Almost surely, 2^{661005625640093} is an apocalyptic number.

It is an amenable number.

661005625640093 is a deficient number, since it is larger than the sum of its proper divisors (1).

661005625640093 is an equidigital number, since it uses as much as digits as its factorization.

661005625640093 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6998400, while the sum is 53.

The spelling of 661005625640093 in words is "six hundred sixty-one trillion, five billion, six hundred twenty-five million, six hundred forty thousand, ninety-three".