66644266531 has 2 divisors, whose sum is σ = 66644266532. Its totient is φ = 66644266530.

The previous prime is 66644266517. The next prime is 66644266537. The reversal of 66644266531 is 13566244666.

66644266531 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66644266531 - 2²¹ = 66642169379 is a prime.

It is a super-2 number, since 2×66644266531² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66644266537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33322133265 + 33322133266.

It is an arithmetic number, because the mean of its divisors is an integer number (33322133266).

Almost surely, 2^66644266531 is an apocalyptic number.

66644266531 is a deficient number, since it is larger than the sum of its proper divisors (1).

66644266531 is an equidigital number, since it uses as much as digits as its factorization.

66644266531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3732480, while the sum is 49.

The spelling of 66644266531 in words is "sixty-six billion, six hundred forty-four million, two hundred sixty-six thousand, five hundred thirty-one".