660136403736421 has 2 divisors, whose sum is σ = 660136403736422. Its totient is φ = 660136403736420.

The previous prime is 660136403736367. The next prime is 660136403736457. The reversal of 660136403736421 is 124637304631066.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 660131533650625 + 4870085796 = 25693025^2 + 69786^2 .

It is a cyclic number.

It is not a de Polignac number, because 660136403736421 - 2²³ = 660136395347813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (660136403736461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330068201868210 + 330068201868211.

It is an arithmetic number, because the mean of its divisors is an integer number (330068201868211).

Almost surely, 2^{660136403736421} is an apocalyptic number.

It is an amenable number.

660136403736421 is a deficient number, since it is larger than the sum of its proper divisors (1).

660136403736421 is an equidigital number, since it uses as much as digits as its factorization.

660136403736421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7838208, while the sum is 52.

The spelling of 660136403736421 in words is "six hundred sixty trillion, one hundred thirty-six billion, four hundred three million, seven hundred thirty-six thousand, four hundred twenty-one".