66530036381 has 2 divisors, whose sum is σ = 66530036382. Its totient is φ = 66530036380.

The previous prime is 66530036369. The next prime is 66530036389. The reversal of 66530036381 is 18363003566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64229299225 + 2300737156 = 253435^2 + 47966^2 .

It is a cyclic number.

It is not a de Polignac number, because 66530036381 - 2¹⁰ = 66530035357 is a prime.

It is a super-2 number, since 2×66530036381² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66530036389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33265018190 + 33265018191.

It is an arithmetic number, because the mean of its divisors is an integer number (33265018191).

Almost surely, 2^66530036381 is an apocalyptic number.

It is an amenable number.

66530036381 is a deficient number, since it is larger than the sum of its proper divisors (1).

66530036381 is an equidigital number, since it uses as much as digits as its factorization.

66530036381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 233280, while the sum is 41.

The spelling of 66530036381 in words is "sixty-six billion, five hundred thirty million, thirty-six thousand, three hundred eighty-one".